Answer to Question #136220 in General Chemistry for Jmowns

Question

A solution of sulfuric acid was made by dissolving 20 grams of 98 percent sulfuric acid in 250 ml of water. Express the concentration of this solution in percent by weight

Answer 1

98% sulphuric acid means in 100 g sulphuric acid source exact amount of sulphuric acid, H2SO4 present 98 g.

So in 20 g, exact amount of H2SO4 present

= (98×20) \100

= 19.6 g H2SO4 present

( as density of solution is not given we ignore the volume of sulphuric acid and take the volume of solution as volume of solvent)

Now concentration of H2SO4 in%(m/v)

= (amount of sulphuric acid in gram × 100) \volume of solution in ml

= (19.6×100) \250

= 1960\250

= 7.84 %(w/v) ans.