91Ó°ÊÓ

(a) What is the molar mass of ribose \(\left(\mathrm{C}_{5} \mathrm{H}_{10} \mathrm{O}_{5}\right)\) ? (b) What is the mass of \(3.87\) moles of ribose? (c) How many ribose molecules are there in \(3.87\) moles? (d) How many oxygen atoms are there in \(3.87\) moles of ribose? (e) What is the mass in grams of the oxygen atoms in part (d)?

Can the actual yield ever be greater than the theoretical yield for a chemical reaction?

Sodium metal reacts with water to form aqueous sodium hydroxide and hydrogen gas. (a) Write a balanced chemical equation for this reaction. (b) Which reactant is limiting if \(100.0 \mathrm{~g}\) of \(\mathrm{Na}\) and \(4.00\) moles of water are used?

Which has the greatest mass: 1 mole of ethylene gas \(\left(\mathrm{C}_{2} \mathrm{H}_{4}\right), 1\) mole of carbon monoxide gas, or 1 mole of nitrogen gas \(\left(\mathrm{N}_{2}\right) ?\)

What is the maximum possible value of the percent yield of a chemical reaction?

(a) What is the molar mass of sucrose \(\left(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\right) ?\) (b) What is the mass of \(1.25\) moles of sucrose? (c) How many sucrose molecules are in \(1.25\) moles? (d) How many hydrogen atoms are in \(1.25\) moles of sucrose? (e) What is the mass in grams of the hydrogen atoms in part (d)?

Aluminum metal burns in chlorine gas to form aluminum chloride. (a) Write a balanced chemical equation for this reaction. (b) Which reactant is limiting if \(100.0 \mathrm{~g}\) of \(\mathrm{Al}\) and \(5.00\) moles of \(\mathrm{Cl}_{2}\) are used?

Copper(I) oxide reacts with solid carbon to form copper metal. Carbon dioxide gas is the other product of this reaction. (a) Write the balanced chemical equation for this reaction. (b) Coke is a cheap, impure form of solid carbon that is often used industrially. If a sample of coke is \(95 \%\) C by mass, determine the mass in kilograms of coke needed to react completely with \(1.000\) ton of copper(I) oxide. \([1\) ton \(=2000 \mathrm{lb} ; 1 \mathrm{~kg}=2.205 \mathrm{lb}]\)

Consider a \(5.00-\mathrm{g}\) sample of silver nitrate, \(\mathrm{AgNO}_{3}(s)\) (a) How many moles of \(\mathrm{AgNO}_{3}\) are in this sample? (b) How many moles of \(\mathrm{O}\) are in this sample? (c) How many grams of \(\mathrm{N}\) are in this sample? (d) How many Ag atoms are in this sample?

Nitrogen and fluorine react to form nitrogen trifluoride according to the balanced chemical equation \(\mathrm{N}_{2}(g)+3 \mathrm{~F}_{2}(g) \rightarrow 2 \mathrm{NF}_{3}(g)\) For each of the following reaction mixtures, choose the limiting reactant: (a) \(0.50 \mathrm{~mol} \mathrm{~N}_{2}(g)\) and \(0.50 \mathrm{~mol} \mathrm{~F}_{2}(g)\) (b) \(12.0 \mathrm{~mol} \mathrm{~N}_{2}(g)\) and \(20.0 \mathrm{~mol} \mathrm{~F}_{2}(g)\) (c) \(2.5 \mathrm{~mol} \mathrm{~N}_{2}(g)\) and \(7.5 \mathrm{~mol} \mathrm{~F}_{2}(g)\) (d) 100 molecules \(\mathrm{N}_{2}(g)\) and 500 molecules \(\mathrm{F}_{2}(g)\) (e) \(5.00 \mathrm{~g} \mathrm{~N}_{2}(g)\) and \(15.0 \mathrm{~g} \mathrm{~F}_{2}(g)\) (f) \(20.0 \mathrm{mg} \mathrm{N}_{2}(g)\) and \(70.0 \mathrm{mg} \mathrm{F}_{2}(g)\)