Chemistry Past Questions And Answers
Which of the following processes leads to increase in entropy?
- A) mixing of a sample of NaCl and sand
- B) condensation of water vapour
- C) boiling of a sample of water
- D) cooling a saturated solution
The following are major gaseous pollutants except. Options
- A) CO
- B) CO2
- C) SO2
- D) CFC
Which of the following statements about rare gases are correct?
- A. Their outermost shells are fully filled
- B. They are generally unreactive
- C. Their outermost shells are partially filled
- D. They have lone pair of
A correct electrochemical series can be obtained from Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Ag, Au by interchanging Options
- A) Al and Mg
- B) Zn and Fe
- C) Zn and Pb
- D) Pb and H
Environmental pollution problems are generally more severe in countries which have
- A. dense population
- B. low birth rate
- C. great land mass
- D. limited industries
25cm3 of a 0.2 mol dm3 solution of Na2CO3 requires 20 cm3 of a solution of HCl for neutralization. The concentration of the HCl solution is
- A. 0.5 mol dm3
- B. 0.6 mol dm3
- C. 0.2 mol dm3
- D. 0.4 mol dm3
An element, Y has the electronic configuration of 1s\(^2\) 2s\(^2\) 2p\(^6\) 3s\(^2\) 3p\(^3\),
- A) Y is a period III element
- B) Y contains three electrons in the outer shell
- C) Y is a transition metal
- D) Y can engage in bonding with the s and p orbitals
If 10.5g of lead (II) trioxonitrate (V) is dissolved in 20cm3 of distilled water at 18oC, the solubility of the solute in mol dm-3 is [Pb = 207, N = 14, O = 16]
- A) 1.60
- B) 5.25
- C) 16.00
- D) 525.00
Which of the following statements about endothermic reaction is correct?
- A. Activation energy is high
- B. A catalyst is required
- C. It occurs reversibly
- D. Heat energy is absorbed
Greenhouse effect can be reduced by controlling
- A. water evaporation
- B. burning wood and fossil fuel
- C. the use of aerosolsers
- D. the use of artificial fertiliz