Question

To prepare an aqueous solution that is 40.0 % by weight of KI, how many kilograms of KI must be added to 1,000 Liters of water? (7 points) e)

Answer 1

Given:-

% by mass of KI (solute) = 40 %

Volume of Water (solvent) = 1000 L. = 1000000 ml

Mass of KI = a = ?

Formula:-

massof KI x 100 PercentagebyKT=massof KI+massofWater

we have,

mass Density = volume

Now, Density of water is 1 g/ml

Therefore,

mass g/ml 1000000ml

mass 1g/ml x 1000000ml 1000000g

Hence mass of water (solvent) = 1000000 g.

Therefore from formula we have,

massof KI PercentagebyMassof KI x 100 massof KI+ masso fWater

a(g) 40 alg)1000000(g) x 100

40 (6)D alg)1000000(g) 100

ag) 0.4 a(g)1000000(g)

a(g)a(g)+ 1000000(g)x0.4

a(g)0.4a(g) +400000(g)]

0.6a(g) = 400000(g)

400000(g) a(g) 666666.669 0.6

Mass of KI = (a) = 666.66 kg.

Therefore, 666.66 kg of KI must be added to 1000 L of water to produce an aqueous solution of 40.0% by mass of KI.