03 Chemical Reactions and Stoichiometry Online Quiz Questions

Balance $\mathrm{Al + Cl_2 \to AlCl_3}$ using the smallest whole-number coefficients. Then state the number of Al atoms and Cl atoms on each side.

For $\mathrm{AgNO_3(aq) + NaCl(aq) \to AgCl(s) + NaNO_3(aq)}$, identify the reaction pattern and explain what evidence indicates that a precipitate forms.

For $\mathrm{HCl + NaOH \to NaCl + H_2O}$, classify the reaction and identify the acid, the base, the salt, and the water.

For $\mathrm{Zn + 2HCl \to ZnCl_2 + H_2}$, identify the reaction category based on the replacement pattern and explain why it is also a redox reaction.

Use $\mathrm{CH_4 + 2O_2 \to CO_2 + 2H_2O}$ to determine how many moles of $\mathrm{O_2}$ are required to react completely with 2.40 mol $\mathrm{CH_4}$, and how many moles of $\mathrm{CO_2}$ form.

For $\mathrm{2Al + 3Cl_2 \to 2AlCl_3}$, chlorine is in excess. Calculate the mass of $\mathrm{AlCl_3}$ produced from 10.8 g Al. Use molar masses of 27.0 g/mol for Al and 133.3 g/mol for $\mathrm{AlCl_3}$, and report your result to three significant figures.

A reaction follows the balanced equation $\mathrm{A + 2B \to AB_2}$. If 3.0 mol A reacts with 4.0 mol B, identify the limiting reactant, calculate the maximum moles of $\mathrm{AB_2}$, and determine how many moles of the excess reactant remain.

Explain the difference between theoretical yield and actual yield. Give two reasons an experiment might produce less than the theoretical yield.

A reaction has a theoretical yield of 24.0 g and an actual yield of 18.6 g. Calculate the percent yield.

What volume of 0.150 M NaOH neutralizes 15.0 mL of 0.300 M HCl? Use $\mathrm{HCl + NaOH \to NaCl + H_2O}$, and show the mole-ratio step.

Using $\mathrm{H_2SO_4 + 2NaOH \to Na_2SO_4 + 2H_2O}$, calculate the volume of 0.500 M NaOH needed to react completely with 40.0 mL of 0.250 M $\mathrm{H_2SO_4}$. Show how the coefficients affect the calculation.

A student calculates the moles in 35.0 mL of a 0.200 M solution by multiplying $0.200$ by $35.0$. Explain the error and calculate the correct amount in moles, showing the volume conversion and units.

Balance $\mathrm{Al} + \mathrm{Cl_2} \rightarrow \mathrm{AlCl_3}$ using the smallest whole-number coefficients. Then state the number of Al and Cl atoms on each side.

For $\mathrm{Zn} + 2\mathrm{HCl} \rightarrow \mathrm{ZnCl_2} + \mathrm{H_2}$, identify the reaction category and explain which element replaces which other element.

For $\mathrm{AgNO_3(aq)} + \mathrm{NaCl(aq)} \rightarrow \mathrm{AgCl(s)} + \mathrm{NaNO_3(aq)}$, identify the reaction pattern and explain what evidence indicates that a precipitate forms.

Classify $\mathrm{CH_4} + 2\mathrm{O_2} \rightarrow \mathrm{CO_2} + 2\mathrm{H_2O}$ and explain how the reactants and products support your classification.

For $\mathrm{HCl} + \mathrm{NaOH} \rightarrow \mathrm{NaCl} + \mathrm{H_2O}$, classify the reaction and identify the acid, the base, the salt, and the other product.

What two features identify an oxidation–reduction (redox) reaction?

For $2\mathrm{Al} + 3\mathrm{Cl_2} \rightarrow 2\mathrm{AlCl_3}$, determine the mole ratio of $\mathrm{AlCl_3}$ to Al in simplest form. Explain why this coefficient ratio is not a mass ratio.

In $2\mathrm{Al} + 3\mathrm{Cl_2} \rightarrow 2\mathrm{AlCl_3}$, chlorine is available in excess. How many moles of $\mathrm{AlCl_3}$ can form from $1.25$ mol Al? Show how the equation's coefficients support your result.

A calculation asks for the mass of product B formed from a given mass of reactant A. Describe the full conversion sequence and indicate where the balanced equation's mole ratio is used.

For $2\mathrm{H_2} + \mathrm{O_2} \rightarrow 2\mathrm{H_2O}$, a mixture contains $3.0$ mol $\mathrm{H_2}$ and $1.0$ mol $\mathrm{O_2}$. Determine the limiting reactant, the theoretical amount of water formed, and the amount of hydrogen left over. Show the product-amount comparison used to decide which reactant is limiting.

A reaction has a theoretical yield of $2.0$ mol product and an actual yield of $1.5$ mol product. Calculate the percent yield and distinguish theoretical yield from actual yield.

What volume of $0.100\ \mathrm{M}$ NaOH is needed to neutralize $30.0\ \mathrm{mL}$ of $0.150\ \mathrm{M}$ HCl? Use $\mathrm{HCl(aq)} + \mathrm{NaOH(aq)} \rightarrow \mathrm{NaCl(aq)} + \mathrm{H_2O(l)}$. Show how you convert the acid volume to moles, apply the mole ratio, and find the base volume.

A student writes Zn + HCl → ZnCl₂ + H₂ and proposes changing HCl to HCl₂ to balance the equation. Write the correctly balanced equation using the original formulas, then verify the number of atoms of each element on both sides.

For AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq), classify the reaction in two relevant ways. Explain the ion exchange and identify the precipitate, using the equation as evidence.

A reaction has a theoretical yield of 18.0 g and an actual yield of 14.4 g. Calculate the percent yield and state what the actual yield represents compared with the theoretical yield.

In 2Al + 3Cl₂ → 2AlCl₃, chlorine is in excess. If 13.5 g Al reacts, what mass of AlCl₃ can form? Use molar masses Al = 27.0 g/mol and AlCl₃ = 133.5 g/mol, and report your answer to three significant figures. Show the conversion from grams of Al to grams of AlCl₃.

What volume of 0.100 M NaOH is needed to neutralize 35.0 mL of 0.150 M HCl? Use HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l). Show how you convert the known solution volume to moles, apply the mole ratio, and find the required NaOH volume.

For $2\mathrm{H_2} + \mathrm{O_2} \rightarrow 2\mathrm{H_2O}$, a mixture contains 5.0 mol H₂ and 3.0 mol O₂. Determine the limiting reactant, the theoretical yield of H₂O, and the amount of excess reactant left unreacted. Show how comparing the product possible from each reactant supports your answer.