Question

18% (w/v) solution of urea (mol. Mass=60) is???

Answer 1

Given:
% of Urea = 18%

18% of Urea =18 over 100 which means 18 gm of urea in 100ml of solution,

Let's find out its molarity with help of formula,

Molarity space equals space fraction numerator Number space of space moles over denominator Volume space of space solutionin space straight L space end fraction space
Number space of space moles space equals space fraction numerator Given space mass space in space gms over denominator Molar space mass end fraction space equals space 18 over 60 space space equals space 0.3 moles space space space......................... left parenthesis since space Mol space mass space of space urea equals 60 right parenthesis

Solution space in space straight L space equals space 100 over 1000 space equals space 0.1 space straight L

Molarity space equals fraction numerator 0.3 space moles over denominator 0.1 space straight L end fraction equals space 3 space straight M