What mass of NaOH is in 250 mL of a 3.0M NaOH solution​

about 30g

Explanation:

Molarity = mol/L

*convert mL to L*

3M=xmol/.25

xmol = .75

*convert to g

.75 mol NaOH * 40g/mol = 30 g

Explanation:

Explanation: It's a 3.0 M solution so 1 litre of solution contains 3 moles of NaOH. 250 ml of solution therefore contains 0.25 x 3 = 0.75 moles of NaOH. The molar mass of NaOH is 39.9971 g/mol, so 250 ml of this solution contains 0.75 x 39.9971 = 29.99 g, or if you round it up 30.0 g.

it is b that is the answer.

it's c (engineer's do their work with mechanical stuff not on any living being)