Selected MCQ

Current Question
Which solution has pH < 7?
  • A. Neutral
  • B. Basic
  • C. Acidic
  • D. Buffer
Correct Answer: C
Explanation:
Acids have pH less than 7.
Related Question 1
Which compound conducts electricity in solution?
  • A. Sugar
  • B. Salt
  • C. Alcohol
  • D. Benzene
Correct Answer: B
Explanation:
Ionic compounds dissociate into ions.
Related Question 2
Ocean acidification is mainly caused by increased dissolution of atmospheric:
  • A. Nitrogen
  • B. Oxygen
  • C. Carbon dioxide
  • D. Methane only
Correct Answer: C
Explanation:
Dissolved (CO_2) forms carbonic acid, lowering seawater pH.
Related Question 3
Which statement is correct for a buffer solution?
  • A. It resists all pH changes regardless of added amount
  • B. It contains a strong acid and strong base in equal amounts
  • C. It resists pH change upon small addition of acid or base
  • D. Its pH is always 7
Correct Answer: C
Explanation:
Buffers work through conjugate acid-base pairs that neutralize small perturbations.
Related Question 4
The pH of a neutral aqueous solution at 25°C is:
  • A. 0
  • B. 7
  • C. 10
  • D. Depends only on solute mass
Correct Answer: B
Explanation:
At 25°C neutral water has ([H^+] = [OH^-] = 10^{-7},\text{M}).