Chemistry exam questions and answers

1.	Thermodynamic standard conditions of temperature and pressure are (A) 0°C and 1 atm (B) 273 k and 101.3 k Pa (C) 298 k and 1 atm (D) 0°C and 101.3 k Pa	Answer: (C)
2.	Three moles of PCl5, three moles of PCI3 and two moles of Clz are taken in a closed vessel. If at equilibrium the vessel has 1.5 moles of PCl5, the number of moles of PCl3 present in it is (A) 5 (B) 3 (C) 6 (D) 4.5	Answer: (D)
3.	Time required for 100 percent completion of a zero order reaction is ______. (A) (B) (C) a k (D)	Answer: (D)
4.	Two gases A and B having the same volume diffuse through a porous partition in 20 and 10 seconds respectively. The molecular mass of A is 49 u. Molecular mass of B will be (A) 25.00 u (B) 50.00 u (C) 12.25 u (D) 6.50 u	Answer: (C)
5.	Vapour pressure of pure 'A' is 70 mm of Hg at 25 °C. It forms an ideal solution with 'B' in which mole fraction of A is 0.8. lf the vapour pressure of the solution is 84 mm of Hg at 25 °C, the vapour pressure of pure 'B' at 25 °C is (A) 70 mm (B) 140 mm (C) 28 mm (D) 56 mm	Answer: (B)
6.	Waxes are esters of (A) glycerol (B) long chain alcohols (C) glycerol and fatty acid (D) long chain alcohols and long chain fatty acids	Answer: (D)
7.	When a sulphur sol is evaporated sulphur is obtained. On mixing with water sulphur sol is not formed. The sol is (A) hydrophilic (B) hydrophobic (C) reversible (D) lyophilic	Answer: (B)
8.	When carbon monoxide is passed over solid caustic soda heated to 200°C, it forms (A) Na2CO3 (B) NaHCO3 (C) HCOONa (D) CH3COONa	Answer: (C)
9.	When compared to DG0 for the formation of Al2O3 , the AG0 for the formation of Cr2O3 is (A) higher (B) lower (C) same (D) unpredicted	Answer: (A)
10.	When conc. H2SO4 is heated with P2 05 , the acid is converted into (A) sulphur (B) sulphur dioxide (C) sulphur trioxide (D) a mixture of sulphur dioxide and sulphur trioxide	Answer: (C)