A 2.52-g sample of a compound containing only carbon, hydrogen, nitrogen, oxygen, and sulfur is burned in excess oxygen to yield 4.23 g of $CO_2$ and 1.01 g of $H_2O$. Another sample of the same compound, of mass 4.14 g, yields 2.11 g of $SO_3$. A third sample, of mass 5.66 g, yields 2.27 g of $HNO_3$. Calculate the empirical formula of the compound.

When $0.684$ g of an organic compound containing only carbon, hydrogen, and oxygen was burned in oxygen, $1.312 \mathrm{~g}$ of $\mathrm{CO}_2$ and $0.805 \mathrm{~g}$ of $\mathrm{H}_2 \mathrm{O}$ were obtained. What is the empirical formula of the compound?

A compound contains only carbon, hydrogen, and oxygen. Combustion of 10.68 mg of the compound yields 16.01 mg

$$CO_2$$

and 4.37 mg

$$H_2O.$$

The molar mass of the compound is 176.1 g/mol. What are the empirical and molecular formulas of the compound?

The elements X and Y form a compound that is 40% X and 60% Y by mass. The atomic mass of X is twice that of Y. What is the empirical formula of the compound?

Seventeen people have been exposed to a particular disease. Each one independently has a 40% chance of contracting the disease. A hospital has the capacity to handle 10 cases of the disease. What is the probability that the hospital's capacity will be exceeded? (a) 0.011 (b) 0.035 (c) 0.092 (d) 0.965 (e) 0.989

Chlorine gas is a diatomic molecule, $Cl_2$. There are 6.00 mol of chlorine atoms in a sample of chlorine gas. How many moles of chlorine gas molecules is this?

A mixture of 50.0 g of S and $1.00 \times 10^{2}$ g of $Cl_2$ reacts completely to form $S_2Cl_2$ and $SCl_2$. Find the mass of $S_2Cl_2$ formed.

A particular coal contains 2.55% sulfur by mass. When the coal is burned, it produces $SO_2$ emissions, which combine with rain water to produce sulfuric acid. Use the formula of sulfuric acid to calculate the mass percent of S in sulfuric acid. Then determine how much sulfuric acid (in metric tons) is produced by the combustion of 1.0 metric ton of this coal. (A metric ton is 1000 kg.)

A compound containing nitrogen and oxygen is decomposed in the laboratory and produces $1.78 \mathrm{~g}$ of nitrogen and $4.05 \mathrm{~g}$ of oxygen. Calculate the empirical formula of the compound.

Three pure compounds form when 1.00-g samples of element X combine with, respectively, 0.472 g, 0.630 g, and 0.789 g of element Z. The first compound has the formula $X_2Z_3$. Find the empirical formulas of the other two compounds.

A hydrate of copper(II) chloride has the following formula: $\mathrm{CuCl}_{2} \cdot x \mathrm{H}_{2} \mathrm{O}$. The water in a 3.41-g sample of the hydrate is driven off by heating. The remaining sample has a mass of 2.69 g. Find the number of waters of hydration (x) in the hydrate.

A phosphorus compound that contains 34.00% phosphorus by mass has the formula $X_3P_2$. Identify the element X.

A particular coal contains 2.5% sulfur by mass. When this coal is burned at a power plant, the sulfur is converted into sulfur dioxide gas, which is a pollutant. To reduce sulfur dioxide emissions, calcium oxide (lime) is used. The sulfur dioxide reacts with calcium oxide to form solid calcium sulfite. If the coal is burned in a power plant that uses 2000.0 tons of coal per day, what mass of calcium oxide is required daily to eliminate the sulfur dioxide?

A mixture of NaCl and NaBr has a mass of 2.00 g and contains 0.75 g of Na. What is the mass of NaBr in the mixture?