Question

How many grams of sodium chloride are needed to prepare 250 mL of a 2% solution?

Answer 1

wouldn't you want .02*250g=5grams?

Answer 2

find the moles of NAOH =250*0.20/1000
no of moles = 0.05
moles=mass/molar mass
so,
mass=moles*molar mass
molar mass of NAOH is =40

so,mass=0.05*40 =2g
mass of NAOH needed is 2g {answer}

3nx ...

Answer 3

58/2*100 = 2900 grams