Question

How much of each of the following substances would you add to water to prepare 1.90 L of a 0.15 M solution?
(a) H2SO4 from "concentrated" (18 M) sulfuric acid
mL
(b) HCl from "concentrated" (12 M) reagent
mL
(c) NiCl2 from the salt NiCl2·6 H2O
g
(d) HNO3 from "concentrated" (16 M) reagent
mL
(e) sodium carbonate from the pure solid
g
If u explained how to do one of them I should be able to do the rest. Thanks!

Answer 1

For solutions use the dilution formula of mL1 x M1 = mL2 x M2

For solids, calculate how many moles you need which is mols = M x L = 0.15 x 1.90 = ?
Then mols = grams/molar mass. You know mols and you have molar mass, solvel for grams.
Note that c wants Nicl2 but weighs NiCl2.6H2O. Since 1 mol NiCl2 is contained in 1 mol NiCl2.6H2O, use molar mass NiCl2.6H2O for this problem.