Chemistry

Solutions and pH Chemistry

400 Questions

Solutions and pH chemistry focus on the acidity or alkalinity of various substances, from human urine to acidic soils. Questions involve titration calculations, molarity determination, and understanding mole fractions. This topic is a staple in the chemistry sections of state and national level competitive exams.

Calculating solution molarityMole fraction calculationpH value interpretationAcidic soils and pHTitration and neutralization

Solutions and pH Chemistry Questions

Multiple choice

Match the entries ||| |---|---| |Term|Definition| |A. Molality|1. The number of equivalent weights of solute per litre of solution| |B. Molarity|2. The number of moles of solute per litre of solvent| |C. Normality|3. The number of moles of solute per kg of solvent|

  1. A – 1; B – 2; C – 3

  2. A – 1; B – 3; C – 2

  3. A – 2; B – 1; C – 3

  4. A – 3; B – 2; C – 1

  5. A – 2; B – 3; C – 1
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Correct answer is A – 3; B – 2; C – 1.

Multiple choice

In man, the pH of saliva varies from

  1. 8.0 to 10.0

  2. 7.5 to 8.0

  3. 7.5 to 9.0

  4. 6.7 to 7.2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Human saliva is slightly acidic to neutral, with pH typically ranging from 6.2 to 7.6. The range of 6.7 to 7.2 represents the normal physiological variation in healthy individuals. Options A, B, and C are incorrect because they indicate alkaline ranges that are not found in normal human saliva.

Multiple choice

The solute particle size in suspensions is

  1. less than 100 nm

  2. more than 10–5 cm

  3. more than 10–8 m

  4. between 1 nm and 100 nm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 The size of solute particles in suspension is more than 10–5 cm.

Multiple choice

Match the following: Name of salt solution|Nature| |a. Sodium carbonate solution|1. Neutral| |b. Ammonium chloride solution|2. Basic| |c. Sodium chloride solution|3. Acidic|

  1. a - 2, b - 3, c - 1

  2. a - 1, b - 3, c - 2

  3. a - 3, b - 2, c - 1

  4. a - 2, b - 1, c - 3

  5. a - 1, b - 2, c - 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the correct option. The nature of sodium carbonate solution is basic. The nature of ammonium chloride solution is acidic. The nature of sodium chloride solution is neutral.

Multiple choice

If 1 mole of H3PO4 is reacted with 1 mole of X(OH)2 as: H3PO4 + X(OH)2 → XHPO4 + 2H2O. Then which of the following statements is correct

  1. The equivalent weight of base is (molecular wt./3)

  2. The eq. wt. of H3PO4 is 98/3

  3. The resulting solution is required 1 mole NaOH for completing neutralisation.

  4. 1 mole X(OH)2 more required 1 mole NaOH for complete neutralisation.

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The resulting solution has still one mole H+ ion to be neutralised, so, 1 mole of NaOH is required for complete neutralisation. Hence, this is a correct option.

Multiple choice

10 g of a sample of Ca(OH)2 is dissolved in 10 ml of 0.5 N HCl solution. The excess of HCl was titrated with 0.2 N NaOH. The volume of NaOH used was 20 cc. Calculate the percentage of Ca(OH)2 in the sample.

  1. 11%

  2. 12%

  3. 1.11%

  4. 2.22%

  5. 99%
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Milli eq. of HCl initially = 10 * 0.5 = 5. Milli eq. of NaOH consumed = milli eq. of HCl in excess     = 10 * 0.2 = 2 Therefore, milli eq. of HCl consumed = Millie q. of Ca(OH)2     = 5 – 2 =3 Therefore, eq. of Ca(OH)2 = (3 / 1000) = 3 * 10^–3 Mass of Ca(OH)2 = (3 * 10^–3) * (74 / 2) = 0.111 g% Ba(OH)2 = (0.111 / 10) * 100 = 1.11%; which is the required solution of the given problem. Hence, this is the correct option.