Chemistry Past Questions And Answers
The hydrolysis of NH4CI gives
- A. an acidic solution
- B. an alkaline solution
- C. a buffer solution
- D. a neutral solution
A particle that contains 8 proton, 9 neutrons and 7 electrons could be written as?
- A. O
- B. O+
- C. O2+
- D. O-
Sieving is a technique used to separate mixtures containing 20% oxygen by volume. Which of the reactants was in excess?
- A) Carbon (II) oxide
- B) Oxygen
- C) Carbon (IV) oxide
- D) Nitrogen
One of these elements is the best reducing agent.
- A) Pb
- B) Rb
- C) Al
- D) In
Consider the cell represented below: Zn/Zn2+(aq) // Cu2+(aq) / Cu(s). Which of the following statements...
- A. Zn is oxidized to Zn2+
- B. Cu is oxidized to Cu2+
- C. It is an electrolytic cell
- D. each single line represents a salt bridge
When excess ethanol is heated to 145oC in the presence of concentrated H2SO4, the product is
- A. ethyne
- B. diethyl sulphate
- C. diethyl ether
- D. acetone
25cm3 of a gas X contains Z molecules at 15oC and 75 mmHg. How many molecules will 25 cm3 of another gas Y contain at the same temperature and pressure?
- A. 2 Y
- B. 2 Z
- C. Z
- D. Y
The above orbital diagram shown the electronic configuration of
- A) chlorine
- B) nitrogen
- C) calcium
- D) neon
Phosphorus is stored under water to prevent it from
- A. Dehydrating
- B. Becoming inert
- C. Smelling
- D. Catching fire
What is the mass percentage of carbon (C) in methane (CH4)? (The molar mass of carbon is approximately 12 g/mol.)
- A. 25%
- B. 12%
- C. 75%
- D. 50%