Pdf question 4 - molarity molality mass percent

Practice Question Solving
1

We want make 255 mL of hydrochloric acid 2.28 mol/L solution. If the mass percent of pure hydrochloric acid in the solute is 74 %, calculate the grams of impure solute needed.

2

HCL=35.5 +1= 36.5 g/mole

2.28 mole/1000ml =X mole/255ml
X=0.58 mole HCL (pure)
0.58 mole * 36.5 g/mole=21.17 g total pure HCL SO 74% is pure
74 pure/100 impure = 21.17 pure / X impure
X=28.6

hope to be helpful !

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