How much sr(oh)2 • 8 h2o (m = 265.76) is needed to prepare 250.0 ml of solution in which [oh]= 0.100m?

The answer is = 3.322grams

The explanation:

1-First we need o get the no.of moles:

moles = molarity * volume(L)

by substitution:

∴ moles = 0.1M * 0.25 L

= 0.025 moles

but we have 2 OH in Sr(OH)2

so moles = 0.025 /2 = 0.0125 moles

2- then we need to get how many grams of it so, we are going to use this formula:

mass = moles * molar mass

by substitution:

∴ mass = 0.0125 * 265.76

= 3.322 grams