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Guess Paper – 2011
CBSE Class – XI
(States Of Matter)
Q1. A vessel of 120 ml capacity contains a certain amount of gas at 35
°C and 1.2 bar pressure. The gas is transferred to another vessel of volume 180
ml at 35 °C. What would be its pressure?
Q2. What will be the pressure of the gaseous mixture when 0.5 L of H2 at
0.8 bar and 2.0 L of dioxygen at 0.7 bar are introduced in a 1L vessel at 27°C?
Q3. A student forgot to add the reaction mixture to the round bottomed
flask at 27 °C but instead he/she placed the flask on the flame. After a lapse
of time, he realized his mistake, and using a pyrometer he found the temperature
of the flask was 477 °C. What fraction of air would have been expelled out?
Q4. What will be the pressure exerted by a mixture of 3.2 g of methane
and 4.4 g of carbon dioxide contained in a 9 dm3 flask at 27 °C ?
Q5. At 0°C, the density of a certain oxide of a gas at 2 bar is same as
that of dinitrogen at 5 bar. What is the molecular mass of the oxide?
Q6. Density of a gas is found to be 5.46 g/dm3 at 27 °C at 2 bar pressure.
What will be its density at STP?
Q7. 34.05 ml of phosphorus vapour weighs 0.0625 g at 546 °C and 0.1 bar
pressure. What is the molar mass of phosphorus?
Q8. Calculate the temperature of 4.0 mol of a gas occupying 5 dm3 at 3.32
Q9. (R = 0.083 bar dm3 K–1 mol–1).
Q10. Pressure of 1 g of an ideal gas A at 27 °C is found to be 2 bar. When 2 g
of another ideal gas B is introduced in the same flask at same temperature the
pressure becomes 3 bar. Find a relationship between their molecular masses.
Q11. The drain cleaner, Drainex contains small bits of aluminum which react with
caustic soda to produce dihydrogen. What volume of dihydrogen at 20 °C and one
bar will be released when 0.15g of aluminum reacts?
Q12. Calculate the total number of electrons present in 1.4 g of dinitrogen gas.
Q13. How much time would it take to distribute one Avogadro number of wheat
grains, if 1010 grains are distributed each second?