AP Chemistry 4.5: Stoichiometric Calculations

Practice AP Chemistry questions on using balanced-reaction coefficients to calculate amounts, identify limiting reactants, and connect stoichiometry with solutions and gases.

Exam points

Explain how intermolecular forces and molecular shape determine boiling point and solubility properties.
Apply structure, polarity and particle-interaction models to predict properties of molecular substances.

[Maximum number: 1]

Answer the following questions about ascorbic acid (vitamin C).

A student combusts a sample of ascorbic acid, $\mathrm{C}_{x} \mathrm{H}_{y} \mathrm{O}_{x}$ , to determine its chemical

composition. The only products of the reaction are 0.2400 mol of $\mathrm{CO}_{2}$ and 2.883 g of $\mathrm{H}_{2} \mathrm{O}$ .

Calculate the number of moles of $\mathrm{H}_{2} \mathrm{O}$ produced.

A (i) For the correct calculated value:

$2.883 \mathrm{~g} \mathrm{H}_{2} \mathrm{O} \times \frac{1 \mathrm{~mol} \mathrm{H}_{2} \mathrm{O}}{18.02 \mathrm{~g} \mathrm{H}_{2} \mathrm{O}}=0.1600 \mathrm{~mol} \mathrm{H}_{2} \mathrm{O}$

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4.5.A—Explain changes in the amounts of reactants and products based on the balanced reaction equation for a chemical… question 1