Answer to Question #55691 in General Chemistry for odonghanro daniel

Question

A solution contains 4 grams of sodium hydroxide in 250ml of solution. If Na=23, O=16 , H=1 and
1cm3
of water weighs1g, what is the concentration of the solution in weight per weight percent?
2.81%
1.92%
1.57%
3.29%

Answer 1

m(NaOH) = 4 g;
1 cm3 of H₂O weights 1 g; V = 250 ml; m(H₂O) = 250 g;
m(the solution) = m(NaOH) + m(H₂O);
m = 254 g;
w = m(the solute)/m(the solution) * 100%
w (NaOH) = 4/254*100% = 1.57%

Answer: 1.57%