‘Black powder’ is a blend of potassium nitrate, carbon and sulfur. Its reaction is represented below. $4\text{KNO}_3(s) + 7\text{C}(s) + \text{S}(s) \rightarrow 3\text{CO}_2(g) + 3\text{CO}(g) + 2\text{N}_2(g) + \text{K}_2\text{S}(s) + \text{K}_2\text{CO}_3(s)$ A sealed tube with black powder has a volume of $10.0\,\text{cm}^3$. After the whole sample reacts, the process produces a pressure of $2 \times 10^6\,\text{Pa}$ and a temperature of $2500\,\text{K}$. The volume occupied by the produced $\text{K}_2\text{CO}_3$ and $\text{K}_2\text{S}$ may be neglected. What is the amount in moles of $\text{KNO}_3$ in the sealed tube?
- A$4.81 \times 10^{-4}$
- B$9.63 \times 10^{-4}$
- C$1.93 \times 10^{-3}$
- D$9.63 \times 10^{-1}$