Some Basic Conc...

If 40 g of ethyl alcohol is dissolved in 50 ml of water, then calculate the weight/volume percentage of ethyl alcohol present in the solution? [Density of ethyl alcohol = 0.8 g/ml].

$$CaCO_3 + 2HCl \rightarrow CaCl_2 + H_2O + CO_2$$

A certain compound has the molecular formula, $$\displaystyle X_{4}O_{6}$$. If $$10$$ g of compound contains $$5.62$$ g of X, the atomic mass of X is approximately :

The hydrated salt, $$\displaystyle Na_{2}SO_{4}.nH_{2}O$$ undergoes 56% loss in weight on heating and becomes anhydrous. The value of n (approx.) will be :

What is the percentage of calcium in calcium carbonate $$(CaCO_3)$$? 

If a $$360 mL$$ sample of helium contains $$0.25$$ moles, how many molecules of chlorine gas would occupy the same volume at the same pressure and temperature?

"All gases have the same number of moles in the same volume at constant temperature and pressure:. This statments belongs to :

Statement 1: At the same temperature and pressure, 1 L of hydrogen gas and  1 L of neon gas have the same mass.
Statement 2: Equal volumes of ideal gases at the same temperature and pressure contain the same number of moles.

$$0.16\ g$$ of an organic compound containing sulphur produces $$0.233\ g$$ of $$BaSO_{4}$$. Percentage of sulphur in the compound is :

How do you determine the mass percent of a solute in a solution?