A student synthesizes calcium oxalate in two reactions. In the first reaction, nitric acid is added to excess calcium carbonate. After the reaction stops, the remaining solid is removed by filtration.

\[ \text{CaCO}_3\text{(s)}+2\text{HNO}_3\text{(aq)}\rightarrow \text{Ca(NO}_3\text{)}_2\text{(aq)}+\text{CO}_2\text{(g)}+\text{H}_2\text{O(l)} \]

The entire filtrate is then combined with sodium oxalate solution.

\[ \text{Ca(NO}_3\text{)}_2\text{(aq)}+\text{Na}_2\text{C}_2\text{O}_4\text{(aq)}\rightarrow \text{CaC}_2\text{O}_4\text{(s)}+2\text{NaNO}_3\text{(aq)} \]

Substance	Mass used or collected	Molar mass
\(\text{CaCO}_3\)	\(20.0\text{ g}\)	\(100\text{ g/mol}\)
\(\text{HNO}_3\)	\(18.9\text{ g}\)	\(63.0\text{ g/mol}\)
\(\text{Na}_2\text{C}_2\text{O}_4\)	\(8.04\text{ g}\)	\(134\text{ g/mol}\)
\(\text{CaC}_2\text{O}_4\)	\(6.14\text{ g}\) collected	\(128\text{ g/mol}\)

Which pair gives the theoretical yield of \(\text{CaC}_2\text{O}_4\) and the overall percent yield of the sequence?