Question

32)6 g urea was dissolved in 500 g of water. Calculate percentage by mass of urea in solution.
Ans: 1.186% by mass​

Answer 1

Answer:

1.186%

Explanation:

We know that

Mass percentage= mass of solute/mass of solution × 100

Now, total mass of soultion after adding urea=500+6

                                                                           =506g

Then,

Mass % = 6g/506g × 100

            =600/506

            =1.186% by mass

Answer 2

Given :

Mass of urea = 6 g

Mass of water = 500 g

To Find :

Mass percentage of urea in solution

Solution :

We know,

The formula for Percentage by mass is  $\frac{Mass of Solute}{Mass of Solution}$ × 100%

Here solute is urea and Solution means (urea + water)

mass of urea = 6 g

mass of solution (urea + water) = 500 + 6 = 506 g

Percentage by mass of urea in solution = $\frac{Mass pf Urea }{(Mass of Urea) + (Mass of Water)}$ ×100%

                                                                      = $\frac{6}{6 + 500}$ × 100%

                                                                      = $\frac{6}{506}$ × 100%

                                                                      = 1.186%

∴ Urea is present 1.186% by mass in the solution.