6 g of Mg completely reacted with dil. HCl at STP, the volume of hydrogen evolved is
[a] 22.4 lit. [b] 11.2 lit. [c] 5.6 lit. [d] 2.0 lit.
Q.-7-
The vapour density of certain gas X is 4 times that of Y. The molecular mass of X is M , the molecular mass of Y is
[a] 4 M [b] 0.5 M [c] 0.25 M [d] 0.33 M
Q.7 ans-c]0.25m
ReplyDeleteQ.7-c]0.25M
ReplyDeleteLet VD of Y be y.
therefore,VD of X=4y.
Here,molecular mass of X=2VD=8y=M
Also,molecular mass of Y=2VD=2y
(i.e-8y/4=M/4=0.25M)
{70 seconds}
Q.6]ans.c]5.6 lit.
ReplyDeleteWhen 24g(1 mole) of Mg is reacted 2g(1 mole) of hydrogen is evolved.
Hence,when 6g(1/4 mole)of Mg is reacted,1/4 mole of hydrogen is obtained.
1 mole of Hydrogen gas at STP=22.4lit. of Hydrogen
hence,1/4 mole of Hydrogen gas=5.6 lit.
{68 seconds}
Q.[c].Time req-55sec
ReplyDeleteQ.[c].Time req-1min