1.101 ques

Asked by lovemaan5500 | 30th Jan, 2019, 11:59: AM

Expert Answer:

Given:
 
Mass of Glauber's salt dissolved = 8.0575 × 10-12 kg
 
                                               = 80.57 gm
 
Molecular formula of Glauber's salt = Na2SO4.10H2O   
 
Molecular weight of Glauber's salt = 322 g/mol
 
 
No. space of space moles space equals fraction numerator 80.6 over denominator 322 end fraction

space space space space space space space space space space space space space space space space space space space space space equals 0.25 space mol

Volume space of space solution space equals space 1 space dm cubed

Density space of space solution colon space 1077.2 space kg divided by straight m cubed space

Density space equals Mass over Volume

Mass space of space solution space equals space space 1077.2 cross times space 1

Mass space of space water space in space solution space equals space 1077.2 space minus space 80.6

space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 996.4 space straight g

We space have comma

Molality space equals space fraction numerator No. space of space moles over denominator Weight space of space solvent space in space Kg end fraction

space space space space space space space space space space space space space equals space fraction numerator 0.25 over denominator 0.996 end fraction

Molality space equals space 0.251 space straight m

Molarity space equals fraction numerator No. space of space moles over denominator Volume space of space solution space in space litre end fraction

space space space space space space space space space space space space space space equals fraction numerator 0.25 over denominator 1 end fraction space

Molarity space equals space 0.25 space straight M

Mole space fraction space of space salt space equals space fraction numerator Moles space of space salt over denominator Moles space of space salt space plus space moles space of space water end fraction

Moles space of space water space equals space fraction numerator 996.4 over denominator 18 end fraction

space space space space space space space space space space space space space space space space space space space space space space space space equals space 55.35 space mol

Mole space fraction space of space salt space equals space fraction numerator 0.25 over denominator 55.35 end fraction

space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals 4.5 space cross times 10 to the power of negative 3 end exponent
space space space space space space space space space space space
 
Molality = 0.251 m
 
Molarity = 0.25 M
 
Moles fraction = 4.5 × 10-3
 
 
 
 
 
 

Answered by Varsha | 30th Jan, 2019, 04:26: PM

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