Q4.Use the information below to answer this question.
A saturated solution of magnesium hydroxide, Mg(OH)2, contains 0.1166 g of Mg(OH)2 in 10.00 dm3 of solution. In this solution the magnesium hydroxide is fully dissociated into ions.
Which one of the following is the concentration of Mg2+(aq) ions in the saturated solution?
A 2.82 × 10^−2 mol dm−3
B 2.00 × 10^−3 mol dm−3
C 2.82 × 10^−3 mol dm−3
D 2.00 × 10^−4 mol dm−3
I've attempted this but I've got a different answer to the mark scheme. I did 0.1166/58.3=0.002 which is apparently wrong. could someone help?