Silver metal reacts with chlorine $\left(\mathrm{Cl}_2\right)$ to yield silver chloride. If $2.00 \mathrm{~g}$ of $\mathrm{Ag}$ reacts with $0.657 \mathrm{~g}$ of $\mathrm{Cl}_2$, what is the empirical formula of silver chloride?

ow many grams of $\mathrm{Mg}$ are needed to react with $25.0 \mathrm{~g}$ of $\mathrm{O}_2$ ? How many grams of $\mathrm{MgO}$ will result?

An alternative method for preparing pure iron from $\mathrm{Fe}_2 \mathrm{O}_3$ (Problem 6.61) is by reaction with carbon monoxide:

$$\mathrm{Fe}_2 \mathrm{O}_3+\mathrm{CO} \longrightarrow \mathrm{Fe}+\mathrm{CO}_2 \text { Unbalanced }$$

(a) Balance the equation. (b) How many grams of $\mathrm{CO}$ are needed to react with $3.02 \mathrm{~g}$ of $\mathrm{Fe}_2 \mathrm{O}_3$ ? (c) How many grams of $\mathrm{CO}$ are needed to react with $1.68 \mathrm{~mol}$ of $\mathrm{Fe}_2 \mathrm{O}_3 ?$

In the preparation of iron from hematite (Problem 6.61), $\mathrm{Fe}_2 \mathrm{O}_3$ reacts with carbon:

$$\mathrm{Fe}_2 \mathrm{O}_3+\mathrm{C} \longrightarrow \mathrm{Fe}+\mathrm{CO}_2 \text { Unbalanced }$$

(a) Balance the equation. (b) How many moles of carbon are needed to react with $525 \mathrm{~g}$ of hematite? (c) How many grams of carbon are needed to react with $525 \mathrm{~g}$ of hematite?

Iron metal can be produced from the mineral hematite, $\mathrm{Fe}_2 \mathrm{O}_3$, by reaction with carbon. How many kilograms of iron are present in $105 \mathrm{~kg}$ of hematite?

Titanium metal is obtained from the mineral rutile, $\mathrm{TiO}_2$. How many kilograms of rutile are needed to produce $100.0 \mathrm{~kg}$ of Tir?

Aspirin is prepared by reaction of salicylic acid $\left(\mathrm{C}_7 \mathrm{H}_6 \mathrm{O}_3\right)$ with acetic anhydride $\left(\mathrm{C}_4 \mathrm{H}_6 \mathrm{O}_3\right)$ according to the following equation: (a) How many grams of acetic anhydride are needed to react with $4.50 \mathrm{~g}$ of salicylic acid? (b) How many grams of aspirin will result? (c) How many grams of acetic acid are formed as a byproduct?

A sample that weighs $107.75 \mathrm{~g}$ is a mixture of $30 \%$ helium atoms and $70 \%$ krypton atoms. How many particles are present in the sample?

A sample that weighs $25.12 \mathrm{~g}$ contains $6.022 \times 10^{23}$ particles. If $25.00 \%$ of the total number of particles are argon atoms and $75.00 \%$ are another element, what is the chemical identity of the other constituent?

What is the mass in grams of each of the following samples? (a) $0.0015 \mathrm{~mol}$ of sodium (b) $0.0015 \mathrm{~mol}$ of lead (c) $0.0015 \mathrm{~mol}$ of diazepam (Valium), $\mathrm{C}_{16} \mathrm{H}_{13}$ ClN $_2 \mathrm{O}$

An average cup of coffee contains about $125 \mathrm{mg}$ of caffeine, $\mathrm{C}_8 \mathrm{H}_{10} \mathrm{~N}_4 \mathrm{O}_2$. How many moles of caffeine are in a cup? How many molecules of caffeine? Caffeine

The "lead" in lead pencils is actually almost pure carbon, and the mass of a period mark made by a lead pencil is about $0.0001 \mathrm{~g}$. How many carbon atoms are in the period?

Iron(II) sulfate, $\mathrm{FeSO}_4$, is prescribed for the treatment of anemia. How many moles of $\mathrm{FeSO}_4$ are present in a standard $300 \mathrm{mg}^2$ tablet? How many iron(II) ions?

What is the molecular weight of cholesterol if $0.5731 \mathrm{~mol}$ weighs $221.6 \mathrm{~g}$ ?