A 2g sample of H2 at certain temperature T degree celcius and volume V litres exerts pressure P atm . D is an isotope of hydrogen . which one ov the following wuld exert pressure of P atm at T degree celcius. ?

A. 2g of D2 at vol V litres
B. 4g of D2 at vol V/2 litres
C.a mixture of 1g H2 and 2g D2 at vol V litres
D. a mixture of 2g H2 and 1g D2 at vol 2V litres
kindly explain clearly the logic behind this question n measuremnt :)

Question

A 2g sample of H2 at certain temperature T degree celcius and volume V litres exerts pressure P atm . D is an isotope of hydrogen . which one ov the following wuld exert pressure of P atm at T degree celcius. ? 

A. 2g of D2 at vol V litres 
B. 4g of D2 at vol V/2 litres 
C.a mixture of 1g H2 and 2g D2 at vol V litres 
D. a mixture of 2g H2 and 1g D2 at vol 2V litres 
kindly explain clearly the logic behind this question n measuremnt :)

anonymous · Answer

a mole of one gas exerts the same pressure when at same temperature and  volume as a mole of another gas. 
pV = n R T

D2 has twice the molecular weight as H2, so it takes twice the weight of D2 to have the same number of moles as H2.

This should help you.