61.  At constant Volume for a fixed number of a moles of a gas, the pressure of the gas increases with the rise in temperature due to

A. Increase in average molecules speed

B. Increase rate of collisions amongst

C. Increase in molecular attraction

D. Increase in mean free path

62.  Equal mass of methane and oxygen are mixed in an empty container at $$250^{\circ}C$$ the fraction of the total pressure exerted by $$O_{2}$$ is

A. $$\frac{1}{2}$$

B. $$\frac{2}{3}$$

C. $$\frac{1}{3}\times \frac{273}{298}$$

D. $$\frac{1}{3}$$

63.

Find the true and false statements from the following on the basis of given graph

1. Maxwell and Boltz mann had studied the distribution of molecules between different possible speeds
2. This graph is known as maxwell’s distribution curve in which kinetic energy and molecular speed of gas is studied.
3. The fraction molecues with very high or very low speed is very high
4. Inecresing the speed fraction also increasing Which becomes maximum and then deereases.
5. The top portion of curve indicates maximum fraction of molewles and the speed of molecules is called most probable speed which is indicated by $$\alpha$$
6. On increasing temperature the collison of molecules increases and speed of molecules decreases

A. TTFTTF

B. TFTTFT

C. FTTFFT

D. TTTTFF

64.  When a real gas behaves as an ideal gas ?

A. Inter molecular attraction among molecules are negligible then

B. At very low pressure and high temperature then

C. When molecular size is very very small and negligible to the volume of container then

D. In all the above condition

65.  What is the ratio of diffusion rate of $$^{238}\textrm{UF}_{6}$$ and $$^{235}\textrm{UF}_{6}$$ When these gases are diffused under the same condition of temperature and pressure ?

A. 0.09953

B. 1.0047

C. 1.0

D. 10487

66.   Molecular mass of $$SO_{2}$$ gas is 4 times than $$CH_{4}$$ therefore

A. Being $$SO_{2}$$ and $$CH_{4}$$ both gases, they diffuse with same rate

B. $$SO_{2}$$ gas will diffuse 4 times factor than that of $$CH_{4}$$

C. Diffusion of $$SO_{2}$$ gas is half than that of $$CH_{4}$$

D. $$CH_{4}$$ gas found 4 times faster than $$SO_{2}$$

67.  50 ml $$O_{2}$$ gas diffused in 80 sec, What time will be required to diffuse same volume of He gas?

A. 22.89 sec

B. 28.29 sec

C. 92.82 sec

D. 24.29 sec

68.  What is the mass (weight) of $$6.022\times 10^{22}$$ oxygen molecules ?

A. 32 gms

B. 3.2 gms

C. 16 gms

D. 1.6 gms

69.  How many molecules of $$5\ O_{2}$$ gas will be present in 5.6 litre volume of STP ?

A. $$1.5\times 10^{23}$$

B. $$6.002\times 10^{23}$$

C. $$7.52\times 10^{23}$$

D. $$3.01\times 10^{23}$$

70.  Molar mass of $$CaCO_{3}$$ = 100 gm/mole, how many molecules are present in 20 gm $$\left (CaCO_{3} \right )$$ ?
A. $$12.44\times 10^{23}$$
B. $$1.2044\times 10^{23}$$
C. $$1.2044\times 10^{25}$$
D. $$1.2044\times 10^{22}$$