molecules present in 20g H2O

 

Asked by kusumgchouhan001 | 22nd Jun, 2018, 09:33: AM

Expert Answer:

Given:
 
Weight of water = 20 g
 
Molar space mass space of space straight H subscript 2 straight O space equals space 18

1 space mole space of space straight H subscript 2 straight O space equals space 6.023 cross times 10 to the power of 23 space end exponent molecules

therefore space 18 space straight g space of space straight H subscript 2 straight O space equals space 6.023 cross times 10 to the power of 23 space end exponent molecules

therefore 20 space straight g space of space straight H subscript 2 straight O space equals fraction numerator 6.23 cross times 10 to the power of 23 cross times 20 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 equals space 6.92 cross times 10 to the power of 23 space molecules
 
 
20 g water contains 6.92×1023 molecules.
 

Answered by Varsha | 24th Jun, 2018, 06:56: PM