Question

A tank contains 90 kg of salt and 2000 L of water. Pure water enters a tank at the rate 8 L/min. The solution is mixed and drains from the tank at the rate 4 L/min. (a) What is the amount of salt in the tank initially?

Answer 1

To find the initial amount of salt in the tank, calculate the concentration of salt in the solution using the formula for concentration.

Step-by-step explanation:

To find the amount of salt in the tank initially, we need to calculate the mass of salt in the solution. The concentration of salt in the solution can be found using the formula:

Concentration of salt (in kg/L) = Mass of salt (in kg) / Volume of solution (in L)

Given that the solution contains 90 kg of salt and 2000 L of water, we can substitute these values into the formula:

Concentration of salt = 90 kg / 2000 L = 0.045 kg/L

Therefore, the initial amount of salt in the tank is 0.045 kg/L * 2000 L = 90 kg.