Chapter 2: Acids, Bases and Salts

Solution

Citric acid is found in citrus fruits like lemon, orange, and grapefruit. Vinegar contains acetic acid, curd contains lactic acid, and tamarind contains tartaric acid.

Solution

Phenolphthalein is colourless in acidic and neutral solutions and turns pink in basic solutions. This is one of the most commonly used indicators in chemistry labs.

Solution

The answer for 'an organic acid' is: CH3COOH (Acetic acid)

Solution

The answer for 'a mineral acid' is: H2SO4 (Sulphuric acid)

Solution

The answer for 'an acid with pH close to 1' is: Concentrated HCl

Solution

The answer for 'the acid present in lemon juice' is: Citric acid

Solution

The answer for 'a diprotic acid (donates 2 H+ ions)' is: H2SO4 (Sulphuric acid)

Solution

The answer for 'a strong acid' is: HCl (Hydrochloric acid)

Solution

The answer for 'a weak acid' is: CH3COOH (Acetic acid)

Solution

The answer for 'the acid present in vinegar' is: Acetic acid (CH3COOH)

Solution

Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)↑

The gas evolved is hydrogen. It can be tested by bringing a burning matchstick near the mouth of the test tube — hydrogen burns with a characteristic 'pop' sound.

Solution

Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂↑

The CO₂ gas, when passed through lime water (Ca(OH)₂ solution), reacts to form an insoluble white precipitate of CaCO₃, making the lime water milky.

Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s)↓ + H₂O(l)

Solution

The reaction between an acid and a base to form salt and water is called a neutralisation reaction. It is exothermic in nature.

Example: HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l) + Heat

Solution

On the pH scale (0-14), pH 3 is well below 7 (neutral). The lower the pH, the more acidic the solution. pH 3 indicates a strongly acidic solution. For comparison, lemon juice has a pH of about 2.2 and vinegar about 2.5-3.0.

Solution

Since bee stings inject formic acid (methanoic acid), a basic substance is needed to neutralise it. Baking soda (NaHCO₃) is mildly basic and is applied on bee stings for relief.

Note: For wasp stings (which are basic), vinegar (acidic) is applied.

Solution

Baking soda is NaHCO₃, which is chemically called sodium hydrogen carbonate (also known as sodium bicarbonate). It is used in baking, as an antacid, and in fire extinguishers.

Solution

Plaster of Paris (CaSO₄·½H₂O) is obtained by heating gypsum (CaSO₄·2H₂O) at 373 K (100°C).

CaSO₄·2H₂O →^{373 K} CaSO₄·½H₂O + 1½H₂O

If gypsum is heated above 373 K, it forms anhydrous CaSO₄ (dead burnt plaster), which cannot be set with water.

Solution

Bleaching powder (CaOCl₂) is prepared by passing chlorine gas over dry slaked lime:

Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O

Note: CaO (quicklime) is NOT used — it must be slaked lime Ca(OH)₂.

Solution

Human blood is slightly basic with a pH in the narrow range of 7.35 – 7.45. If the blood pH goes below 7.0 or above 7.8, it can be life-threatening. The body uses buffer systems to maintain this pH precisely.

Solution

An olfactory indicator is a substance whose smell changes in the presence of an acid or a base. Examples include onion (smell disappears in base) and vanilla extract (smell disappears in base). These indicators are useful for visually impaired students.

Solution

pH = -log[H+] = -log(10^(-5)) = 5

Solution

pH = -log[H+] = -log(10^(-11)) = 11

Solution

pH = -log[H+] = -log(10^(-7)) = 7

Solution

pH = -log[H+] = -log(10^(-13)) = 13

Solution

pH = -log[H+] = -log(10^(-9)) = 9

Solution

pH = -log[H+] = -log(10^(-2)) = 2

Solution

pH = -log[H+] = -log(10^(-6)) = 6

Solution

pH = -log[H+] = -log(10^(-10)) = 10

Solution

pH = -log[H+] = -log(10^(-1)) = 1

Solution

pH = -log[H+] = -log(10^(-8)) = 8

Solution

pH = -log[H+] = -log(10^(-12)) = 12

Solution

pH = -log[H+] = -log(10^(-4)) = 4

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 10 / (250/1000) = 10 x 1000 / 250 = 40.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 34 / (200/1000) = 34 x 1000 / 200 = 170.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 39 / (250/1000) = 39 x 1000 / 250 = 156.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 12 / (500/1000) = 12 x 1000 / 500 = 24.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 23 / (100/1000) = 23 x 1000 / 100 = 230.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 28 / (250/1000) = 28 x 1000 / 250 = 112.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 49 / (250/1000) = 49 x 1000 / 250 = 196.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 41 / (250/1000) = 41 x 1000 / 250 = 164.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 12 / (200/1000) = 12 x 1000 / 200 = 60.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 6 / (500/1000) = 6 x 1000 / 500 = 12.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 20 / (100/1000) = 20 x 1000 / 100 = 200.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 10 / (100/1000) = 10 x 1000 / 100 = 100.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 13 / (500/1000) = 13 x 1000 / 500 = 26.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 9 / (100/1000) = 9 x 1000 / 100 = 90.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 7 / (200/1000) = 7 x 1000 / 200 = 35.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 20 / (100/1000) = 20 x 1000 / 100 = 200.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 8 / (1000/1000) = 8 x 1000 / 1000 = 8.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 44 / (250/1000) = 44 x 1000 / 250 = 176.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 38 / (100/1000) = 38 x 1000 / 100 = 380.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 35 / (250/1000) = 35 x 1000 / 250 = 140.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 20 / (100/1000) = 20 x 1000 / 100 = 200.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 17 / (250/1000) = 17 x 1000 / 250 = 68.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 16 / (500/1000) = 16 x 1000 / 500 = 32.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 45 / (1000/1000) = 45 x 1000 / 1000 = 45.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 17 / (250/1000) = 17 x 1000 / 250 = 68.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 26 / (250/1000) = 26 x 1000 / 250 = 104.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 17 / (500/1000) = 17 x 1000 / 500 = 34.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 49 / (250/1000) = 49 x 1000 / 250 = 196.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 47 / (250/1000) = 47 x 1000 / 250 = 188.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 36 / (200/1000) = 36 x 1000 / 200 = 180.0 g/L

Solution

pH = -log[H+] = -log(10^(-3)) = 3

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 41 / (200/1000) = 41 x 1000 / 200 = 205.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 42 / (250/1000) = 42 x 1000 / 250 = 168.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 20 / (250/1000) = 20 x 1000 / 250 = 80.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 8 / (1000/1000) = 8 x 1000 / 1000 = 8.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 10 / (250/1000) = 10 x 1000 / 250 = 40.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 11 / (1000/1000) = 11 x 1000 / 1000 = 11.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 19 / (100/1000) = 19 x 1000 / 100 = 190.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 16 / (500/1000) = 16 x 1000 / 500 = 32.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 15 / (250/1000) = 15 x 1000 / 250 = 60.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 23 / (200/1000) = 23 x 1000 / 200 = 115.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 5 / (250/1000) = 5 x 1000 / 250 = 20.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 22 / (100/1000) = 22 x 1000 / 100 = 220.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 16 / (100/1000) = 16 x 1000 / 100 = 160.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 29 / (200/1000) = 29 x 1000 / 200 = 145.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 30 / (100/1000) = 30 x 1000 / 100 = 300.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 44 / (500/1000) = 44 x 1000 / 500 = 88.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 2 / (250/1000) = 2 x 1000 / 250 = 8.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 19 / (250/1000) = 19 x 1000 / 250 = 76.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 44 / (500/1000) = 44 x 1000 / 500 = 88.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 21 / (250/1000) = 21 x 1000 / 250 = 84.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 42 / (200/1000) = 42 x 1000 / 200 = 210.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 50 / (250/1000) = 50 x 1000 / 250 = 200.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 29 / (500/1000) = 29 x 1000 / 500 = 58.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 5 / (500/1000) = 5 x 1000 / 500 = 10.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 13 / (500/1000) = 13 x 1000 / 500 = 26.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 36 / (200/1000) = 36 x 1000 / 200 = 180.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 13 / (100/1000) = 13 x 1000 / 100 = 130.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 47 / (250/1000) = 47 x 1000 / 250 = 188.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 15 / (200/1000) = 15 x 1000 / 200 = 75.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 45 / (500/1000) = 45 x 1000 / 500 = 90.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 46 / (250/1000) = 46 x 1000 / 250 = 184.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 38 / (200/1000) = 38 x 1000 / 200 = 190.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 30 / (200/1000) = 30 x 1000 / 200 = 150.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 48 / (500/1000) = 48 x 1000 / 500 = 96.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 17 / (200/1000) = 17 x 1000 / 200 = 85.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 33 / (250/1000) = 33 x 1000 / 250 = 132.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 39 / (1000/1000) = 39 x 1000 / 1000 = 39.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 37 / (100/1000) = 37 x 1000 / 100 = 370.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 17 / (500/1000) = 17 x 1000 / 500 = 34.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 27 / (200/1000) = 27 x 1000 / 200 = 135.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 45 / (1000/1000) = 45 x 1000 / 1000 = 45.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 11 / (200/1000) = 11 x 1000 / 200 = 55.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 16 / (1000/1000) = 16 x 1000 / 1000 = 16.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 43 / (1000/1000) = 43 x 1000 / 1000 = 43.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 42 / (500/1000) = 42 x 1000 / 500 = 84.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 39 / (200/1000) = 39 x 1000 / 200 = 195.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 35 / (1000/1000) = 35 x 1000 / 1000 = 35.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 5 / (100/1000) = 5 x 1000 / 100 = 50.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 40 / (500/1000) = 40 x 1000 / 500 = 80.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 10 / (100/1000) = 10 x 1000 / 100 = 100.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 46 / (1000/1000) = 46 x 1000 / 1000 = 46.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 14 / (250/1000) = 14 x 1000 / 250 = 56.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 12 / (1000/1000) = 12 x 1000 / 1000 = 12.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 23 / (200/1000) = 23 x 1000 / 200 = 115.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 20 / (500/1000) = 20 x 1000 / 500 = 40.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 50 / (200/1000) = 50 x 1000 / 200 = 250.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 20 / (200/1000) = 20 x 1000 / 200 = 100.0 g/L

Solution

Concentration (g/L) = mass of solute / volume of solution (in L)

= 34 / (200/1000) = 34 x 1000 / 200 = 170.0 g/L

Solution

Tooth enamel is made of calcium phosphate, which is the hardest substance in the body. However, it starts dissolving when the pH in the mouth drops below 5.5. Bacteria in the mouth produce acids from sugar and food particles, lowering the pH. This is why we should brush regularly and avoid excessive sweet/acidic foods.

Using toothpaste (which is basic) helps neutralise the acid and protect tooth enamel.

Solution

Acids show acidic behaviour (and hence change litmus colour) only when they produce H⁺ (or H₃O⁺) ions. This happens only in the presence of water. Dry HCl gas cannot produce H⁺ ions, so it does not behave as an acid and cannot change the colour of dry litmus paper.

Solution

Dissolving an acid in water is a highly exothermic process — it releases a large amount of heat.

If water is added to concentrated acid (e.g., H₂SO₄), the small amount of water added initially absorbs so much heat that it may boil instantly, causing the acid to splash out and cause severe burns.

When acid is added to water, the large volume of water can absorb the heat without boiling, making the process safe and controlled.

Memory aid: Think of it as 'Do as you oughta — add acid to water' (oughta rhymes with water).

Solution

Problem: Soil pH = 4.5 (acidic). Most crops grow best at pH 6.5 – 7.0.

Solution 1: Add quicklime (CaO) to the soil. CaO reacts with the acid in the soil to neutralise it:

CaO + H₂O → Ca(OH)₂ (which then neutralises the acid)

Solution 2: Add slaked lime (Ca(OH)₂) directly. Being a base, it directly neutralises the excess acid in the soil, raising the pH towards neutral.

Why it works: Both substances are bases that undergo neutralisation with the acidic components in the soil, converting them into neutral salts and water, thus raising the pH.

Solution

Step 1: Heat baking soda

2NaHCO₃(s) →^Δ Na₂CO₃(s) + H₂O(g) + CO₂(g)

Baking soda decomposes on heating to give anhydrous sodium carbonate.

Step 2: Recrystallisation

Na₂CO₃(s) + 10H₂O(l) → Na₂CO₃·10H₂O(s)

The anhydrous sodium carbonate is dissolved in water and allowed to crystallise, forming washing soda with 10 molecules of water of crystallisation.

Uses of washing soda:

1. Water softening: It removes permanent hardness of water by precipitating dissolved calcium and magnesium salts.
2. Manufacturing: Used in the manufacture of glass, soap, and paper.

Solution

Metal oxides react with acids in the same way bases do — forming salt and water:

CuO(s) + 2HCl(aq) → CuCl₂(aq) + H₂O(l)

Since this is the same pattern as base + acid → salt + water, metal oxides are classified as basic oxides.

Solution

Some amphoteric metals like zinc and aluminium react with both acids and bases to produce hydrogen gas.

2NaOH(aq) + Zn(s) → Na₂ZnO₂(aq) + H₂(g)↑

Copper, iron, and silver do not react with NaOH solution.

Solution

When Plaster of Paris is mixed with water, it undergoes a hydration reaction and sets into a hard solid — gypsum:

CaSO₄·½H₂O + 1½H₂O → CaSO₄·2H₂O

(Plaster of Paris + Water → Gypsum)

This setting is a slightly exothermic process and the material expands slightly, making it ideal for taking accurate moulds and casts.

Why moisture-proof storage? If Plaster of Paris absorbs moisture from the air, it will slowly convert back to gypsum and lose its setting ability. It will become hard and useless before even being used. Hence, it must always be stored in airtight, moisture-proof containers.

Solution

Sodium carbonate is a salt of a strong base (NaOH) and a weak acid (H₂CO₃). Such salts form basic solutions with pH > 7. The strong base 'dominates' over the weak acid.

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 34}{39} = 0.174\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 20}{40} = 0.25\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 19}{26} = 0.073\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 26}{16} = 0.812\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 46}{24} = 0.479\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 45}{40} = 0.281\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 23}{34} = 0.135\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 45}{12} = 0.75\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 20}{11} = 0.455\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 47}{13} = 1.808\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 14}{31} = 0.09\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 36}{35} = 0.206\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 22}{15} = 1.467\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 14}{30} = 0.093\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 42}{48} = 0.219\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 46}{48} = 0.24\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 25}{12} = 0.417\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 42}{31} = 1.355\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 17}{25} = 0.068\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 43}{20} = 0.43\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 20}{37} = 0.135\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 42}{47} = 0.179\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 47}{17} = 2.765\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 11}{28} = 0.196\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 12}{38} = 0.079\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 15}{21} = 0.714\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 10}{41} = 0.122\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 20}{37} = 0.054\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 33}{39} = 0.169\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 20}{41} = 0.244\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 28}{31} = 0.181\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 20}{32} = 0.125\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 40}{19} = 0.211\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 20}{36} = 0.056\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 35}{33} = 0.265\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 50}{30} = 0.833\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 38}{22} = 1.727\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 36}{35} = 1.029\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 50}{14} = 0.714\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 46}{32} = 1.438\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 18}{27} = 0.667\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 14}{27} = 0.052\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 43}{15} = 0.573\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 49}{16} = 0.613\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 48}{29} = 0.331\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 50}{32} = 0.156\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 40}{23} = 1.739\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 22}{29} = 0.076\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 24}{36} = 0.067\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 15}{23} = 0.652\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 20}{22} = 0.227\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 25}{44} = 0.284\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 44}{28} = 1.571\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 29}{32} = 0.091\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 18}{32} = 0.113\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 44}{25} = 1.76\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 39}{24} = 0.406\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 32}{41} = 0.39\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 48}{36} = 0.133\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 40}{46} = 0.217\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 43}{37} = 0.116\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 41}{17} = 0.241\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 40}{22} = 0.455\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 28}{14} = 0.2\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 30}{36} = 0.208\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 43}{10} = 0.86\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 29}{34} = 0.171\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 31}{26} = 0.238\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 24}{50} = 0.048\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 13}{32} = 0.081\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 38}{45} = 0.169\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 14}{13} = 0.108\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 38}{29} = 0.131\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 33}{37} = 0.089\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 38}{49} = 0.388\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 43}{48} = 0.448\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 31}{21} = 0.738\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 37}{35} = 0.211\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 44}{11} = 4.0\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.5 \times 13}{32} = 0.203\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 31}{21} = 0.148\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 37}{17} = 0.544\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 39}{37} = 1.054\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 44}{49} = 0.224\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{1.0 \times 28}{24} = 1.167\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.25 \times 23}{38} = 0.151\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 12}{32} = 0.038\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 10}{18} = 0.056\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.2 \times 30}{18} = 0.333\) M

Solution

For neutralization: \(M_1 V_1 = M_2 V_2\) (monoprotic acid and base)

\(M_2 = \frac{M_1 V_1}{V_2} = \frac{0.1 \times 11}{39} = 0.028\) M

Solution

Water of crystallisation is the fixed number of water molecules chemically bound to each formula unit of a salt in its crystalline form. These water molecules give the crystals their shape, colour, and structure.

Example: Copper sulphate pentahydrate — CuSO₄·5H₂O

• Each unit of CuSO₄ has 5 molecules of water of crystallisation.
• The blue colour of copper sulphate crystals is due to these water molecules.

When heated:

CuSO₄·5H₂O(s) →^Δ CuSO₄(s) + 5H₂O(g)

• Blue crystals turn white (anhydrous CuSO₄ is white).
• If water is added back to the white powder, it turns blue again.

This reversible colour change is used as a test for water.

Other examples:

• Gypsum: CaSO₄·2H₂O (2 molecules of water)
• Washing soda: Na₂CO₃·10H₂O (10 molecules of water)

Solution

The Chlor-Alkali process involves the electrolysis of an aqueous solution of sodium chloride (brine).

Equation: 2NaCl(aq) + 2H₂O(l) →^electricity 2NaOH(aq) + Cl₂(g) + H₂(g)

At the anode (positive electrode): Chlorine gas (Cl₂) is produced.

At the cathode (negative electrode): Hydrogen gas (H₂) is produced.

Near the cathode: Sodium hydroxide (NaOH) solution forms.

Products and Uses:

1. NaOH (Sodium hydroxide): De-greasing metals, soap and detergent making, paper manufacturing.
2. Cl₂ (Chlorine): Water purification, manufacturing of PVC and CFCs, disinfecting swimming pools.
3. H₂ (Hydrogen): Used as fuel, in the manufacture of ammonia (Haber process), margarine production.

The process is called 'Chlor-Alkali' because chlorine and alkali (NaOH) are the main products.

Solution

Increasing order of pH:

Order: Gastric juice < Lemon juice < Pure water < Blood < Milk of magnesia

Substances with pH < 7 are acidic, pH = 7 is neutral, and pH > 7 are basic.

Solution

Observations:

1. Brisk effervescence — vigorous bubbles of a colourless gas are seen.
2. The solid dissolves in the acid gradually.
3. The solution remains colourless (NaCl solution is colourless).

Balanced equation:

Na₂CO₃(s) + 2HCl(aq) → 2NaCl(aq) + H₂O(l) + CO₂(g)↑

Testing the gas:

Pass the evolved gas through lime water (Ca(OH)₂ solution). If the lime water turns milky (white precipitate), the gas is confirmed as CO₂:

Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s)↓ + H₂O(l)

If excess CO₂ is passed, the milkiness disappears as soluble Ca(HCO₃)₂ forms:

CaCO₃(s) + H₂O(l) + CO₂(g) → Ca(HCO₃)₂(aq)