Copper(II) nitrate crystals are made by reacting nitric acid with an excess of malachite. Malachite has the formula $\text{Cu(OH)}_2\cdot\text{CuCO}_3$, $(M_r = 221.0)$. A sample of $12.0\,\text{g}$ of malachite is added to $30.0\,\text{cm}^3$ of $1.50\,\text{mol dm}^{-3}$ nitric acid. What mass of malachite remains unreacted after the reaction has finished?
- A$2.05\,\text{g}$
- B$2.49\,\text{g}$
- C$7.03\,\text{g}$
- D$9.51\,\text{g}$