Question

A geochemist measures the concentration of salt dissolved in Lake Parsons and finds a concentration of 21.0 gL⁻¹. The geochemist also measures the concentration of salt in several nearby non-isolated lakes and finds an average concentration of 6.67 gL⁻¹.
Assuming the salt concentration in Lake Parsons before it became isolated was equal to the average salt concentration in nearby non-isolated lakes, calculate the percentage of Lake Parsons which has evaporated since it became isolated. Round each of your answers to significant digits.

Answer 1

Answer:

The percentage of Lake Parsons which has evaporated since it became isolated is 68.24%.

Explanation:

The concentration of salt dissolved in Lake Parson = 21.0 g/L

= In 1 L of lake Parson  water = 21.0 g of salt

The concentration of salt in several nearby non-isolated lakes = 6.67  g/L

The salt concentration in Lake Parsons before it became isolated = 6.67 g/L

In 1 L of lake water = 6.67 g of salt

If 1 L of lake Parson  water has 6.67 g of salt. Then 21.0 grams of salt will be in ;

$\frac{1}{6.67}\times 21.0 L = 3.15 L$

Water evaporated = 3.15 L - 1 L = 2.15 L

The percentage of Lake Parsons which has evaporated since it became isolated:

$\frac{2.15 L}{3.15 L}\times 100=68.25\%$