Chemistry

Solutions and pH Chemistry

451 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

If NaOH is added to the solution of CH3COOH

  1. H+ ions increases

  2. pH decreases

  3. C2H3O2- increases

  4. HC2H3O2 increase
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

CH3COOH + NaOH  CH3COONa + H2O The salt formed is strong electrolyte. It gives large concentration of CH3COO- (C2H3O2- ions) and Na+ ions.

Multiple choice

A water treatment plant treating 10 mld of water requires 20 mg/I of filter Alum, Al2 (SO4)3.18 H2O. The water has 6 mg/l of alkalinity as CaCo3 (Al = 26.97, S = 32, O = 16, H = 1, Ca = 40, and C = 12).

Total alkalinity requirement (106 mg per day as CaCO3) matching filter Alum, shall be

  1. 180

  2. 120

  3. 90

  4. 60
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The alkalinity requirement is based on the stoichiometry of the reaction between alum and alkalinity. 1 mg of alum reacts with 0.45 mg of alkalinity as CaCO3. For 20 mg/l of alum and 10 mld, the calculation yields 90 mg/l equivalent.

Multiple choice

A water treatment plant treating 10 mld of water requires 20 mg/I of filter Alum, Al2 (SO4)3. 18 H2O. The water has 6 mg/l of alkalinity as CaCo3 (Al = 26.97, S = 32, O = 16, H = 1, Ca = 40, and C = 12).

Quantity of Quick Lime required (106 mg per year as CaO) shall be

  1. 2132

  2. 3000

  3. 4132

  4. 6132
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Quick lime (CaO) is added to provide the necessary alkalinity. Using the stoichiometric relationship between alum and lime, the required amount is calculated based on the daily dosage and converted to an annual requirement.

Multiple choice

What is neutral pH?

  1. 0

  2. 1

  3. 7

  4. 5
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

On the pH scale, which ranges from 0 to 14, a value of 7 is considered neutral. Values below 7 are acidic, and values above 7 are alkaline.

Multiple choice reactions of acids and bases properties of acids and bases acids, bases and salts acids and bases chemistry

When $KHSO _{4}$ is added to concentrated solution of $H _{2}SO _{4}$, the acidity of the solution ?

  1. Increases

  2. Decreases

  3. Remains constant

  4. Can't be predicted
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When $KHSO _4$ is added to concentrated $H _2SO _4$, the acidity remains constant.

Because $H _2SO _4$ is highly concentrated, it's acidity won't increase by adding $KHSO _4$ .

Multiple choice reactions of acids and bases properties of acids and bases acids, bases and salts acids and bases chemistry

In which case of mixing a strong acid and a base each of $1$N concentration, temperature rise is highest?

  1. $20$ ml, acid + $30$ ml alkali
  2. $10$ ml, acid + $40$ ml alkali
  3. $20$ ml, acid + $20$ ml alkali
  4. $30$ ml, acid + $20$ ml alkali
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

More amount of acid reacts with equal amount of base, higher the amount of heat releases.

So, $20ml$ of acid+$20ml$ of alkali.