sandstone contains 30% by weight of CaCO3, and the remaining is SiO2. 1g is dissolved in 200ml of 1 mol per litre of HCL...what will the concentration of calcium in the solution?
The 1 g sample is 30% CaCO3 so the mass CaCO3 is 0.3 g. CaCO3 is 40% Ca so that is 0.3 x 0.40 = 0.12 g Ca.
moles Ca = g/atomic mass.
M = mols/L = moles/0.200 L.