pH and pOH scale; Simple calculations - Jamb Chemistry Past Questions and Answers

Question 1:

• JAMB 2019

The pH of four solutions W, X, Y, Z are 4, 6, 8, 10 respectively, therefore

A. None of these solutions is acidic
B. The pH of Y is made more acidic by addition of distilled water
C. Z is the most acidic solution
D. W is the most acidic solution
E. X is neutral

Question 2:

• JAMB 1978

The pH of four solutions W, X, Y, Z are 4, 6, 8, 10 respectively, therefore

A. None of these solutions is acidic
B. The pH of Y is made more acidic by addition of distilled water
C. Z is the most acidic solution
D. W is the most acidic solution
E. X is neutral

Question 3:

• JAMB 1984

Which of the following mixtures would result in a solution of pH greater than 7?

A. 25.00 cm³ of 0.05 M H₂SO₄ and 25.00cm³ of 0.50 M Na₂CO₃
B. 25.00 cm³ of 0.05 M H₂SO₄ and 25.00 cm³ of 0.10 M NaHCO₃
C. 25.00 cm³ of 0.11 MH₂SO₄ and 25.00cm³ 0. 10 M NaOH
D. 25.00cm³ of 0.11 MH₂ SO₄ and 50.00 cm³ of 0.05 M NaOH
E. 25.00cm³ of 0.25 M H₂SO₄ and 50.00cm³ of 0.20 M NaOH

Question 4:

• JAMB 1985

Some properties of chemical substances are mentioned below... i. sour taste ii. slippery touch iii. yields alkaline gas with ammonium salt iv. has pH less than 7 v. turns phenolphthalein pink.
Which of the above are NOT typical properties of alkalis?

A. I, iv and v
B. Iv and v
C. I and iv
D. Ii and v
E. Ii, iii and iv

Question 5:

• JAMB 1986

Which of the following salts when dissolved in water will NOT give the corresponding pH value?

A. NaHSO₄, pH < 5
B. Na₂CO₃, pH > 8
C. Na₂Cl,pH = 7
D. NaHCO, pH < 6