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Chemistry Question on Mole concept and Molar Masses

What is the concentration of sugar (C12H22O11) in mol L–1 if its 20 g are dissolved in enough water to make a final volume up to 2L?

Answer

Molarity (M) of a solution is given by,
= Number  of moles  of  soluteVolume of  solution in  litres\frac {\text {Number \ of\ moles \ of \ solute}}{\text {Volume\ of \ solution\ in \ litres}}

= Mass of sugar / molar  mass of  sugar2L\frac {\text {Mass\ of\ sugar / molar \ mass\ of \ sugar} }{2L}

= 20g/[(12×12)+(1×22)+(11×16)]g2L\frac {20g / [(12 × 12) + (1 × 22) + (11 × 16)]g}{2L}

=20g/342g2L\frac {20 g / 342 g}{2L}

= 0.0585 mol2L\frac {0.0585\ mol}{2L}
= 0.02925 molL−10.02925\ mol L^{-1}
∴ Molar concentration of sugar = 0.02925 molL−10.02925\ mol L^{-1}