Question

Calculate the volume of ethanol in 300ml solution of 30 % v/v aqueous solution of ethanol.

Answer 1

Answer:

first keep 29 as sol and multiply it by 30

Answer 2

Answer:

V(C_2H_5OH)=\frac{300mL\times1000g}{700g}=428.6mLV(C

2

H

5

OH)=

700g

300mL×1000g

=428.6mL

The density of ethanol equals 0.789 g/mL.

Now, moles of ethanol per 1 kg of water can be calculated:

n(C_2H_5OH)=\frac{m}{M}=\frac{\rho\times{V}}{M}=\frac{0.789g/mL\times428.6mL}{46.07g/mol}=7.34moln(C

2

H

5

OH)=

M

m

=

M

ρ×V

=

46.07g/mol

0.789g/mL×428.6mL

=7.34mol

Therefore, the molal concentration is 7.34 m.

Answer: 7.34 m

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