The diagram shows that each test tube W, X, Y and Z contains $25\,\text{cm}^3$ of a $0.1\,\text{mol dm}^{-3}$ salt solution. W: $\text{BaCl}_2\text{(aq)}$, X: $\text{MgCl}_2\text{(aq)}$, Y: $\text{BaCl}_2\text{(aq)}$, Z: $\text{MgCl}_2\text{(aq)}$. Then $25\,\text{cm}^3$ of $0.1\,\text{mol dm}^{-3}$ $\text{NaOH(aq)}$ is poured into test tubes W and X, while test tubes Y and Z receive $25\,\text{cm}^3$ of $0.1\,\text{mol dm}^{-3}$ $\text{H}_2\text{SO}_4\text{(aq)}$. For W and X, which test tube has the larger pH, and for Y and Z, which test tube produces the larger mass of precipitate?
- Ahigher pH: W; greater mass of precipitate: Y
- Bhigher pH: W; greater mass of precipitate: Z
- Chigher pH: X; greater mass of precipitate: Y
- Dhigher pH: X; greater mass of precipitate: Z