Some Basic Conc...

The percentage of $${P}_{2}{O}_{5}$$ in diammonium hydrogen phosphate $$[{(N{H}_{4})}_{2}HP{O}_{4}]$$ is : 

A $$1000$$ g sample of $$NaOH$$ contains $$3$$ moles of $$O$$ atom, what is the purity of $$NaOH$$?

The $$\%$$ loss in weight after heating a pure sample of potassium chlorate (Molecular weight $$= 122.5$$ g/mol) will be:

A mineral consists of an equimolar mixture of the carbonates of two bivalent metals. One metal is present to the extent of $$15.0\%$$ by weight. $$3.0$$ g of the mineral on heating lost $$1.10$$ g of $$CO_2$$. The percent by weight of other metal is :

The simplest formula of a compound containing $$50$$% of element $$X$$ (Atomic mass $$=$$ $$10$$) and $$50$$% of the element $$Y$$ (Atomic mass $$=$$ $$20$$) by weight is: 

If the percentage of water of crystallization in $$MgSO_4.xH_2O$$ is $$13\%$$, then what is the value of $$x$$?

Mole fraction of ethanol in ethanol-water mixture is $$0.25$$. Hence, the percentage concentration of ethanol by weight of the mixture is:

A hydrate of $$Na_2SO_3$$ has $$50\%$$ water by mass. It is :

A mixture of $$CuSO_4.5H_2O$$ and $$MgSO_4.7H_2O$$ was heated until all the water was driven off. If $$5.0$$ g of mixture gave $$3$$ g of anhydrous salt, what was the percentage by mass of $$CuSO_4.5H_2O$$ in the original mixture?