Some Basic Conc...

What is the correct order of occurance (% by weight) in air of Ne, Ar and Kr ?

$$1$$ mole of oxygen gas weighs ______________

What percent of a sample of nitrogen must be allowed to escape if its temperature, pressure, and volume are to be changed from $$220^oC$$,3 atm and 1.65 L to $$110^oC$$, 0.7 atm and 1 L respectively?

Mole fraction of glycerine $$(C_{ 3 }H_{ 5 }(OH)_{ 3 })$$ in a solution of 36 g of water and 46 g of glycerine is :

0.132 g of an organic compound gave 50 ml of $$N_2$$ at NTP. The weight percentage of nitrogen in the compound is close to 

The density of gas is 0.0002136 g/mL.  Its vapour density is :- 

At $${\text{2}}{{\text{5}}^{\text{o}}}{\text{C}}$$ the density of $${\text{15}}\;{\text{M}}\;{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}\;{\text{is}}\;{\text{1}}{\text{.8}}\;{\text{g}}\;{\text{c}}{{\text{m}}^{ - 3}}.$$ Thus, mass percentage of $${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}$$ is aqueous solution is 

All homologues of which of the following hydrocarbons have the same percentage composition 

From $$\ 2 \ mg$$ calcium $$1.2\times 10^{19}$$ atoms are removed. The number of $$g$$ - atoms of calcium left is $$(Ca=40)$$:

Molecular mass of dry air is ________________.