K. Nayak

CHEMISTRY TEST

TOTAL MARKS: 130 TIME: 60 MIN

SECTION – I (Total Marks: 90)

(Single Correct Choice Type)

This section contains 30 multiple choice questions. Each question has 4 choices (A), (B), (C) and (D) out of

which ONLY ONE is correct.

Q1. Equal masses of ethane and hydrogen are mixed in an empty container at 25°C. The fraction of total

pressure exerted by hydrogen is

(a) 1 : 2 (b) 1 : 1 (c) 1 : 16 (d) 15 : 16

Q2. One mole of N2O4 gas at 300 K is kept in a closed container at 1 atm. It is heated to 600 K. When 20% by

mass N2O4 decomposes to NO2 (g). The resulting pressure in the container would be

(a) 1.2 atm (b) 2.4 atm (c) 2.0 atm (d) 1.0 atm

Q3. A gas will approach ideal behaviour at

(a) low temperature, low pressure (b) low temperature, high pressure

(c) high temperature, low pressure (d) high temperature, high pressure

Q4. Three containers A, B, C of equal volume contain oxygen, neon, and methane, respectively at same

temperature and pressure. The increasing order of their masses is

(a) A < B < C (b) B < C < A (c) C < A < B (d) C < B < A

Q5. The volume of 2.8 g of CO at 27°C and 0.0821 atm is

(a)30 L (b) 3 L (c) 0.3 L (d) 1.5 L

Q6. Which of the following pair contains gases heavier than N2?

(a)O2, SO2 (b) SO2, He (c) He, H2 (d) dry air, SO2

Q7. A cylinder of cooking gas can with stand a pressure of 14.9 atm. The pressure gauge of the cylinder

indicates 12 atm at 300 K. Due to sudden fire in the building, temperature starts rising. The temperature at

which the cylinder will explode is

(a)362.5 K (b) 382.5 K (c) 472.5 K (d) 372.5 K

Q8. 20% of N2O4 molecules are dissolved in a sample of gas at 27°C and 760 torr pressure. The density of

equilibrium mixture is

(a)3.1 gL–1 (b) 6.2 gL–1 (c) 12.4 gL–1 (d) 18.6 gL–1

Q9. When 28 of a gas A is introduced into an evacuated flask kept at 25°C, the pressure is found to be 1 atm.

If 3 g of another gas B is then added to the same flask, the total pressure becomes 1.5 atm at the same

temperature. Assuming ideal behaviour of gases, the ratio of molecular weights MA : MB

(a)1 : 3 (b) 3 : 1 (c) 2 : 3 (d) 3 : 2

Q10. The molar volume of He is 44.8 L at

(a) 373 K and 1 atm (b) 273 K and 1 atm (c) 273 K and 0.5 atm (d) 373 K and 0.5 atm

Q11. At room temperature the volume of a drop of water is 0.0018 ml. The number of water molecules present in it is

(a) 4.84 1017 (b) 1.084 1018 (c) 6.023 1019 (d) 6.023 1023

Q12. If 1021 molecules are removed from 200 mg of CO2, then the no. of moles of CO2 left will be

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(a) (b) (c) (d)

Q13. Density of water at room temperature is 1.0 gml-1. How many molecules are there in one drop of water, if its volume is 0.05 ml?

(a) (b) (c) (d)

Q14. When the same amount of zinc is treated separately with excess of sulphuric acid and excess of NaOH,

the ratio of the moles of hydrogen evolved is :

(a) 1 : 1 (b) 1 : 2 (c) 2 : 1 (d) 2 : 3.

Q15. Avogadro number is the :

(a) weight of any substance in gram (b) weight of one litre of a gas at S.T.P.

(c) weight in gramx 6.02x 1023 (d) number of molecules in a mole.

Q16. At 0°C, and 0.5 atm, 4.48 litre NH3 gas

(a) contains 0.20 mole NH3 (b) weighs 1.70 g

(c) contains 6.02 x 1023 molecules (d) contains 0.40 mole NH3.

Q17. Weight of 112 mL of oxygen at NTP on liquefaction would be

(a) 0.32 g (b) 0.64 g (c) 0.16 g (d) 0.96 g

Q18. A flask of gaseous CCl4 was weighed at measured temperature and pressure. CCl4 was replaced by O2

at the same temperature and pressure. The mass of the CCl4 vapour will be

(a) five times as heavy as O2 (b) one fifth heavy as compared to O2

(c) same as that of O2 (d) twice as heavy as O2

Q19. Which does not represent isobar given by Charles’ law?

Q20. If the density of a certain gas at 30°C and 768 Torr is 1.35 k g /m 3, then density at STP is

(a) 1.48 kg/m3 (b) 1.27 kg/m3 (c) 1.35 kg/m3 (d) 1.00 kg/m3

Q21. A 34.0 L cylinder contains 212 g O2 gas at 27°C. What mass of O2 (g) must be released to reduce the

pressure to 2.463 atm?

(a) 103.2 g (b) 108.8 g (c) 100.0 g (d) 32.0 g

Q22. A 1.00 L vessel containing 1.00 g H2 gas at 27°C is connected to a 2.00 L vessel containing 88.0 g CO2

gas, at also 27°C. When the gases are completely mixed, total pressure is

(a) 20.525 atm (b) 4.105 atm (c) 16.420 atm (d) 730.69 atm

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Q23. In a gaseous mixture at 20°C the partial pressure o f the components are,

Volume percent of H2 is

(a) 26.67 (c) 80.00 (b) 73.33 (d) 20

Q24. I, II, III are three isotherms respectively at T1, T2 and T3. Temperature will be in order

Q25. N2 + 3H2→2NH3.1 mol N2 and 4 mol H2 are taken in 15 L flask at 27°C. After complete conversion of N2

into NH3,5 L of H2O is added. Pressure set up in the flask is

Q26. The density of neon will be minimum at

(a) STP (b) 0°C, 2 atm (c) 273°C, 1 atm (d) 273°C, 2 atm

Q27. A flask contains 12 g of a gas of relative molecular mass 120 at a pressure of 100 atm was evacuated by

means of a pump until the pressure was 0.01 atm. Which of the following is the best estimate of the number

of molecules left in the flask? (N0 = 6×1023 mol-1)

(a) 6 x 1019 ( b ) 6 x 1018 (c) 6 x 1017 ( d ) 6 x 1013

Q28. Which of the following is not the correct set of pressure and volume at constant temperature?

Q29. A sample of gas at 0°C and 1.00 atm pressure occupies 3.00 L. What change in temperature is necessary

to adjust the pressure of that gas to 1.5 atm after it has been transferred to a 2.00 L container?

(a) 273° (b) 0° (c) 5° (d) 10°

Q30. In the following reaction, we start with 2 mol of N2 and 5 mol of H2 exerting a total pressure of 7 atm at a

given temperature in a closed vessel. When 50% of N2 is converted into NH3

N2 + 3H2 → 2NH3 partial pressure of NH3 is

(a) 2.8 atm (b) 2 atm (c) 3.2 atm (d) 4 atm

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SECTION – II (Total Marks: 40)

(Multiple Correct Choice Type)

This section contains 10 multiple choice questions. Each question has four choices (A), (B), (C) and (D) out

of which ONE OR MORE may be correct.

Q31. To which of the following gaseous mixture (s) Dalton’s law is at 25ºC applicable

(a) NH3 and HCl (b) CO2 and CO (c) H2 and He (d) NO and CO

Q32. One mole of following (s) will have 22.4L at NTP

(a) He (b) H2O (c) CCl4 (d) SO2

Q33. The numerical value of Gas constant R is/are —

(a) 0.0821 L atm K–1M–1 (b) 8.31 JK–1M–1 (c) 0.821 L atm K–1M–1 (d) 1.99 Cal K–1M–1

Q34. Arrange the following in order of increasing density—

(I) O2 at 25ºC, 1 atm; (II) O2 at 0ºC, 2 atm;(III) O2 at 273ºC, 1 atm;

(a) III < I < II (b) I < II < III (c) III < II < I (d) II < I < III

Q35. Select correct statements.

Q36. Consider following equations

Boyle’s law is represented by

(a) II, IV (b) II, III (c) I, II (d) I, III, IV

Q37. The volume of a gas increases by a factor of 2 while the pressure decreases by a factor of 3. Given that

the number of moles is unaffected, the factor by which the temperature changes is

(a) 3/2 (b) 3 x 2 (c) 2/3 (d) 1/6

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Q38. Equal masses of methane and oxgen are mixed in an empty container at 25°C. The fraction of the total

pressure exerted by oxygen is

Q39. Dalton’s law of partial pressure is applicable to which one of the following systems?

(a) NH3 + HCl (b) NO + O2 (c) H2 +Cl2 (d) CO+ H2

Q40. Which of the following is the Boyle plot at very low pressure?

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