13. What is an oxidation-reduction reaction? 14. Calcium reacts with oxygen to form calcium oxide. Which reactant is oxidized in this reaction? 15. Is the following sentence true or false? When calcium reacts with oxygen, each calcium atom gains two electrons and becomes a calcium ion with a charge of \( 2- \). 16. Is the following sentence true or false? Oxygen must be present in order for an oxidation-reduction reaction to take place. 17. The process in which an element gains electrons during a chemical reaction is called

Concentrated NaOH is 19.0 M . Determine the volume in mL of the concentrated solutio required to produce 1800 mL of 1.77 M NaOH

What mass in grams of \( \mathrm{NaHCO}_{3} \) is required to make 59.3 mL of 2.68 M solution?

\begin{tabular}{ll}\hline HCN \\ \hline \( \mathrm{NO}_{2}^{-} \) \\ \hline \hline \( \mathrm{CN}^{-} \) \\ \hline \( \mathrm{HNO}_{2} \) & and acid and base on the reactant side are \( \square \), respectively. \\ \hline\end{tabular}

Concentrated HCl is 12.0 M . Determine the volume in mL of the concentrated solution required to produce 5500 mL of 0.250 M HCl .

If the \( \left[\mathrm{H}_{3} \mathrm{O}^{+}\right] \)is less than \( \left[\mathrm{OH}^{-}\right] \)in aqueous solution, then the solution is said to be