General Chemistry Exam - Flashcards 2

Calculate the mass of oxygen ($O_2$) required to completely react with 10 g of hydrogen ($H_2$) to form water ($H_2O$). The balanced equation is $2H_2 + O_2 \rightarrow 2H_2O$.

A 5.0 g sample of impure calcium carbonate ($CaCO_3$) is reacted with 50.0 mL of 1.0 M HCl. The excess HCl is then titrated with 0.5 M NaOH, requiring 20.0 mL to reach the endpoint. Calculate the percentage of $CaCO_3$ in the original sample. Molar mass of $CaCO_3$ is 100 g/mol.

In the reaction $C + O_2 \rightarrow CO_2$, if 12 g of $C$ reacts with 40 g of $O_2$, which is the limiting reagent?