Some Basic Conc...

A balloon contains a certain mass of neon gas. The temperature is kept constant, and the same mass of argon gas is added to the balloon. What happens?

A $$250$$ g sample of a hydrated salt was heated at $${110}^{o}C$$ until all water was driven off. The remaining solid weighed $$160$$ g. From these data, the percent of water by weight in the original sample can be correctly calculated as :

What is the volume occupied by 17.75 g of $$Cl_2$$ at STP?

What is the percent composition by mass of aluminium in a compound of aluminium and oxygen if the mole ratio of $$Al : O$$ is $$2:3$$?

Two gases A and B are taken in same volume containers under similar conditions of temperature and pressure. In container A, there are '2N' molecules of gas A. How many number molecules does container B have? 

What is the molar mass of ammonium carbonate $${({NH}_{4})}_{2}{CO}_{3}$$?

How many grams are there in a $$7.0$$ mole sample of sodium hydroxide?

22.4 litres of a gas at STP weighs 16 g. Identify the gas.

Hydrogen, oxygen and carbon dioxide are taken in containers of $$2 l$$ volume each. Compare the ratio of the number of molecules of the three gases respectively, under same conditions of temperature and pressure.

A mixture contains $$5.0\ g$$ of compound $$X$$ and $$20.0\ g$$ of compound $$Y$$.What is the percent by mass of compound $$X$$?