Question

make 0.8 M MgSO4*7H2O

Answer 1

molecular mass of Magnesium sulphate heptahydrate is 246.4746

suppose we have to make 1 litre (1000 ml) of 0.8 M solution

Molarity (M) is defined as the number of moles of solute per liter of solution.
molarity = moles of solute/liters of solution

M = 246.4746/ 1 = 246.4746

so, to make 1 Molar solution you have to mix 246.4746 gram of Magnesium Heptahydrate in 1 litre of solution.

now, to make 0.8 Molar solution

M = 246.4746X0.8/1 = 197.1797

to make 0.8 Molar solution you have to mix 197.1797 gram of Magnesium Heptahydrate in 1 litre of solvent.

or 19.71 gram in 100 ml of solvent.

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