The molar volume of a gas is 22.4 litres at STP (standard temperature and pressure). 

According to Gay Lussac's law, pressure is directly proportional to temperature at constant volume.
$P\propto T$

Gay Lussac's law states that pressure is directly proportional to temperature at constant volume.

Gay-Lussac's law states that for a given mass and constant volume of  an ideal gas, the pressure exerted on the sides of container is directly propotional to  absolute temperature.

$H _{2}O \rightarrow H^{+} +OH^{-}$
Cathode  :  4$OH^{-} \rightarrow 2H _{2}O +O _{2}+4e^{-} $
Anode :  4$H^{+} +4e^{-} \rightarrow 2H _{2} $
The ratio of volumes of H$ _{2}$ and O$ _{2}$ is $2 : 1$.

As per the Gay Lussac's law of combining volume of gases, the volumes of gaseous reactants and gaseous products bear a simple whole number ratio with each other if they are measured at same temperature and pressure.
In the reaction ${ N } _{ 2 }+{ 3H } _{ 2 }\longrightarrow { 2H } _{ 3 }$, ratio by volume of $N _2,  H _2$ and $ NH _3$ is $1:3:2$. This illustrates law of Gay Lussac's law of combining volumes of gases.

Volume is kept constant and temperature increased.
We have relation, $PV=nRT$
$P\propto T$
Volume constant
So, $P\propto T$ pressure increases as temperature increases.
As we know the speed or average molecular speed depend on temperature.
As temperature increases molecules collide with wall with greater force or momentum.
Also temperature increases, molecular vibrations increases. So molecule will strike with wall more often.
So option C and D.
A is incorrect because there is no change in masses of molecule when we increase temperature.

At constant temperature and pressure, an equal volume of gas contains an equal number of moles.

Law of definite proportions: It states that a given chemical substance (compound) always contains the same elements combined in a fixed proportion by weight. It is also called the law of constant composition.
The law of combining volumes was given by Gay Lussac in 1808. It is applicable only to a gaseous reaction. According to this law, gases combine or are produced in a chemical reaction they do so in a simple ratio by volume provided all gases are at same temperature and pressure. So, the law of definite proportions when expressed in terms of volumes becomes 'Gay-Lussac's Law'. 
Avogadro's law states that 'equal volumes of all gases, at the same temperature and pressure, have the same number of molecules'.
According to Berzelius hypothesis, equal volumes of all gases contain an equal number of atoms under similar conditions of temperature and pressure.

Gay Lussac's law not applicable to formation of $CO _{2}$ from its constituents as carbon and oxygen exist in different physical states.

According to Gay-Lussac's Law :

Gay-Lussac's Law proposes a relationship between the combining volumes of gases with respect to the reactants and gaseous products. According to this law, when gases react together to produce gaseous products, the volumes of reactants and products bear a simple whole number ratio with each other, provided volumes are measured at same temperature and pressure.

atomic weight = $\dfrac{6.4}{specific heat}$

At equal volume of different gases at any definite temperature and pressure have equal no. of particles.

Ans ; A

As 1 mole of a gaseous substance occupies 22.4 litre ($22.4 l =$ gram molar volume)
Volume occupied $=GMV \times 0.01$( gram molar volume )

The given density$=d=\dfrac{m}{volume}$ …….$(1)$

$CCl _3F(mw)=133.5$
$CCl _2F _2(mw)=121$
By given data first we calculate density of solution
$\dfrac {P}{S}=\dfrac {RT}{Mw}\quad R=0.08\quad T=200$
$P=0.08$
for $CCl _3F-S(CCl _3F)=\dfrac {0.08\times 133.5}{0.08\times 200}$
$S=0.6875$
for $CCl _2F _2=\dfrac {0.08\times 121}{0.08\times 200}$
$=0.605$
given data in $(PPt)$
$10^{12}\ gm$ solution contains $=175\ gm$
$10^{3}\ gm$ solution contains $=\dfrac {275}{10^{12}}\times 10^3$
Mass $=275\times 10^{-9}\ gm$
find the volume $d=\dfrac {M}{v}$
$v=\dfrac {1000}{0.6785}=1454.5$
Molarity of $CCl _3F=\dfrac {275\times 10^{-9}}{137.5\times 1454.5}$
$=1.37\times 10^{-12}$
Similarly for $CCl _2F _2$
$10^{12}\ gm$ solution certain $=605$
$10^{3}\ gm$ solution certain $=\dfrac {605}{10^{12}}\times 10^3$
Mass $=605\times 10^{-9}$
$d=\dfrac {m}{v}\quad v=\dfrac {m}{v}=\dfrac {1000}{605}$
$v=1652.89$
molarity $=\dfrac {605\times 10^{-9}}{121\times 1652.89}$
$M=3.02\times 10^{-12}\ mol\ l^3$

Given that,
$m _1=4g$ $V _1=10L$,$P _1=P$,$T _1=T$

In the reaction, $N _{2}+3H _{2}\rightarrow 2NH _{3} $, the ratio by volume of $N _{2},\ H _{2} $ and $ NH _{3}$ is $1 : 3 : 2$. This illustrates the law of Gaseous volumes or Gay Lussac's law of combining volumes of gases.

$P \propto T $
At constant volume and number of moles of a gas, the pressure is directly proportional to the absolute temperature.