An experiment is performed to find the value of $x$ in hydrated lithium hydroxide, $\text{LiOH}\cdot x\text{H}_2\text{O}$. A portion of the solid is heated in a crucible using a Bunsen flame. The sample is fully dehydrated; no decomposition occurs. mass of empty crucible / g = $Q$ mass of crucible with $\text{LiOH}\cdot x\text{H}_2\text{O}$ / g = $R$ mass of crucible and residue after heating / g = $S$ Which equation is used to obtain the correct value of $x$?
- A$\dfrac{S - R}{18}$
- B$\dfrac{R - S}{18}$
- C$\dfrac{23.9(R - S)}{18(S - Q)}$
- D$\dfrac{23.9(S - R)}{18(S - Q)}$