Question

1)
How many grams of Naoh are needed to make 250 ml of a 0.200m solution ​

Answer 1

2.00 g of NaOH are needed.

Explanation:

Use the formula MV=moles, where M is molarity in mol/l and V is volume in liters.

First, convert 250 ml to liters by dividing by 1000.

250lml÷1000=0.250 liters

Now plug the molarity and volume into the formula:

(0.200)(0.250)=0.0500 mol NaOH

Finally, convert moles into mass. The molar mass of NaOH is 39.997 g/mol.

0.0500lmollNaOH1×39.997lglNaOH1lmollNaOH=2.00lglNaOH