Some Basic Conc...

$$800$$ g of a $$40\%$$ solution by weight was cooled. $$100$$ g of solute was precipitated. The percentage composition of remaining solution is :

In diammonium phosphate $$(NH_4)_2HPO_4$$, the percentage of $$P_2O_5$$ is :

Atomic number (Z) of a neutral atom and mass number (A) of an atom are equal to: 

How many g of $$KCl$$ would have to be dissolved in $$60$$ g $${H}_{2}O$$ to give $$20\%$$ by mass of solution?

Calculate the volume occupied by 40 g. of a $$CH_4$$ at S.T.P if its V.D. is 8. 

The volume occupied by 7 grams of nitrogen gas at STP is:

Calculate the volume occupied by 0.01 moles of helium gas at STP.

Find the weight of a substance if its molecular weight is $$70$$ and in the gaseous form it occupies $$10$$ L at $$27^oC$$ and $$760$$ mm $$Hg$$ pressure.

The percentage of $${P}_{2}{O}_{3}$$ in $${H}_{3}P{O}_{3}$$ is:

$$4.4$$ g of $${N}_{2}O$$ occupies $$1.23$$ litres at $$2$$ atm and $$27^oC$$. The volume occupied by same mass of $$C{O}_{2}$$ at $$2$$ atm and $$27^oC$$ is :