Chemistry Past Questions And Answers
C(s) + H2O(g) → H2(g) + CO2(g) ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction is
- A) not feasible
- B) at equilibrium
- C) feasible
- D) exothermic
The mass of an element is 27 and its atomic number is 13. What is the composition of the nucleus of its atom?
- A. 13 electrons and 14 protons
- B. 13 neutrons and 14 protons
- C. 13 protons and 14 neutrons
- D. 13 electrons and 14 neutrons
2.85g of an oxide of copper gave 2.52g of copper on reduction and 1.90g of another oxide gave 1.52g of copper on reduction. The data above illustrates the law of?
- A. constant composition
- B. conservation of mass
- C. reciprocal proportions
- D. multiple proportions
Which of the following molecules has two other positional isomers?
- A) CH3CH2Br
- B) CH3CHBrCH3
- C) CBr2F2
- D) CH2CHBrCH2Br
If the molar mass of X is 36g, the number of moles of X dissolved at 343K is
- A) 0.2 moles
- B) 0.7 moles
- C) 1.5 moles
- D) 2.0 moles
Which of the following metals could be used as sacrifical anode for preventing the corrosion of iron?
- A. Copper
- B. Lead
- C. Magnesium
- D. Silver
Which of the following processes is an endothermic reaction?
- A. Dissolving NH4CI crystals in water
- B. Addition of concentrated H2SO4
- C. Dissolving NaOH pellets in water
- D. Passing SO3 gas into water
Benzene reacts with hydrogen in the presence of nickel catalyst at 180oC to give
- A) xylene
- B) toluene
- C) cyclopentane
- D) cyclohexane
The product of the reaction between ethanol and excess acidified K2Cr2O2 is
- A. ethanal
- B. ethylethanoate
- C. ethanoic acid
- D. ethyne
A sample of water weighs 200.00g at 298K. What is the volume of this quantity of water in cubic meters given that the density of water at 298K is 0.98gcm?3?
- A) 2.04
- B) 2.04
- C) 2.04
- D) 2.04