Question

How much calcium hydroxide (`Ca(OH)_2`), in grams, is needed much produce 1.5 L of a 0.25M solution?

Answer 1

27.75 gm

Explanation:

molarity is defined as = moles of solute / litres of solution

to produce 1.5 L of 0.25 M solution ,
moles of calcium hydroxide needed are = `0.25*1.5`
= 0.375 mol
now amount of calcium hydroxide in grams needed can be calculated by multiplying moles by molar mass : `0.375*74`
= 27.75 gm