What mass of 20% ethyl alcohol solution (mass/volume) of density 1.4g/cc is needed to prepare 200ml solution of ethyl alcohol containing 20g per litre of solution.
(Class 9th Chemistry)
Ans-28g. But how?
Please please assist
Answers
Answer:
Explanation:
The concentration of a solution is often expressed as percent concentration by mass or percent by volume of solute in solution. Percent by mass is calculated from the mass of solute in a given mass of solution. A 5%-by-mass aqueous solution of sodium chloride contains 5 g sodium chloride and 95 g water in each 100 g solution.
Percent by mass = mass of solute
____________________
mass of solution X 100%
If both solute and solvent are liquids, the concentration may be expressed as percent by volume. Both ethyl alcohol and water are liquids; the concentration of alcohol-water solutions is often given as percent by volume. For example, a 95% solution of ethyl alcohol contains 95 mL ethyl alcohol in each 100 mL solution.
Percent by volume = volume of solute
_______________
volume of solution X 100%The concentration of a solution is often expressed as percent concentration by mass or percent by volume of solute in solution. Percent by mass is calculated from the mass of solute in a given mass of solution. A 5%-by-mass aqueous solution of sodium chloride contains 5 g sodium chloride and 95 g water in each 100 g solution.
Percent by mass = mass of solute
____________________
mass of solution X 100%
If both solute and solvent are liquids, the concentration may be expressed as percent by volume. Both ethyl alcohol and water are liquids; the concentration of alcohol-water solutions is often given as percent by volume. For example, a 95% solution of ethyl alcohol contains 95 mL ethyl alcohol in each 100 mL solution.
Percent by volume = volume of solute
_______________
volume of solution X 100%