By 200g. a solution containing 24% potassium nitrate was added 800 ml of water. determine the mass

By 200g. a solution containing 24% potassium nitrate was added 800 ml of water. determine the mass fraction of potassium nitrate in percent

Given:

m (solution KNO3) = 200 g

w% (KNO3) = 24%

V (H2O) = 800 ml

To find:

w% (KNO3 in final solution) -?

Decision:

1) we find the mass of potassium nitrate in the originally given solution:

m (KNO3) = 200 g * 0.24 = 48 g;

2) Find the mass of water added to the solution:

m (H2O) = p * V = 1 g / ml * 800 ml = 800 g;

3) Find the mass of the solution after adding water:

m (solution) = 200 g + 800 g = 1000 g;

4) Find the mass fraction of salt in the final solution:

w% (KNO3) = m (salt): m (solution) * 100% = 48 g: 1000 g * 100% = 4.8%.

Answer: w% (KNO3) = 4.8%.