Laws of Mass Conservation

Q.

What is the molecular weight of air?

Q. Sodium reacts with silver nitrate to produce silver chloride and sodium nitrate. State the law that this equation satisfies?

Q.

A compound of X and Y has the empirical formula ${\mathrm{XY}}_2$. Its vapour density is equal to its empirical formula weight. Determine its molecular formula.

Q.

Five grams of $KCl{O}_3$ yield 3.041 g of $KCl$ and 1.36 L of oxygen at standard temperature and pressure. Do these figures support the law of conservation of mass within limits of $\pm 0.4\%$ error?

1. True

2. False

Q. 10.0 g of ${CaCO}_3$ on heating gives 4.4 g of ${CO}_2$ and 5.6 g of CaO. Which of the following law supports the above observation?

1. Law of constant composition
2. Law of multiple proportions
3. Law of reciprocal proportion
4. Law of conservation of mass

Q. An element $X$ having equivalent mass $E$ forms a general oxide $X_m{O}_n$, its atomic mass should be:

1. $\frac{2\times E\times n}{m}$
2. $2\times m\times E\times n$
3. $\frac{E}{n}$
4. $\frac{M\times E}{2\times n}$

Q. is law of multiple proportion sucessfully explained by Daltons atomic theory ?