The solution has 15% acid, means 15g/100ml.The density is of solution is 1.02g/ml.Mass of solution having 15g of acid= density × volume= 1.02 g/ml × 100 ml=102 gSo, mass of water = mass of solution-mass of acid=102 – 15=87 g Acid present with 87 g of water is 15 g.So, acid present with 100 g of water.=100 X 87/15 = 17.24/100 g of waterThe density of water is 1g/ml.So, the concentration will be 17.24/100 ml of water. So, the mass by volume percentage is 17.24 %. Concept: Mass by volume percentage = (mass of solute/volume of solution) x 100.
Calculation: Given, Mass by mass % = 20% = (mass of solute/mass of solution) × 100 Density of the solution = 1.02 g mL-1 = (mass of solution/ volume of solution ) × 100 We know that, \(Mass\;by\;volume\;\% = \frac{{mass\;of\;solute}}{{volume\;of\;solution}} \times 100\) we have to find the mass of solute =? Volume of the solution =? Also, \(Mass\;by\;mass\;\% = 20\;\% = \frac{{mass\;of\;solute}}{{mass\;of\;solution}} \times 100\) \( \Rightarrow Mass\;of\;Solute = \frac{{20}}{{100}} \times mass\;of\;solution = 0.2 \times mass\;of\;solution\).................(Eq - 1) Also, \(Density\;of\;Solution\;\left( {1.02} \right) = \frac{{mass\;of\;solution}}{{Volume\;of\;solution}}\) \(\Rightarrow Volume\;of\;Solution = \frac{{mass\;of\;solution}}{{Density\;of\;Solution\;\left( {1.02} \right)}}\) .................. (Eq - 2) Putting the values (Eq- 1) and (Eq -2) in \(Mass\;by\;volume\;\% = \frac{{mass\;of\;solute}}{{volume\;of\;solution}} \times 100\) \( \Rightarrow Mass\;by\;volume\;\% = \frac{{\left( {0.2 \times mass\;of\;solution} \right)}}{{\left( {\frac{{mass\;of\;solution}}{{1.02}}} \right)}} \times 100 = 0.2 \times 1.02 \times 100 = 20.4\;\% \) Hence the correct option is 20.4 % Open in App Suggest Corrections 13 |