A tank contains 200 L of fluid in which 30 grams of salt are dissolved. Brine containing 1 g of salt per liter is then pumped into the tank at a rate of 4L/min; the well mixed solution is pumped out at the same rate. Find the concentration of grams of salt in the tank after 30 minutes of the addition of brine.

Respuesta :

Answer:

The final concentration is 0.47 g/L.

Explanation:

Initial solution in the tank:

t = 0

m = 30g

V = 200 L

After 30 minutes (salt pumped into):

t = 30 min

m = 30 g + 30 min x 4g/min = 150g

V = 200 L + 30 min x 4 L/min = 320 L

c = 150 g / 320 L = 0.47 g/L

After 30 minutes (salt pumped out):

t = 30 min

m = 150 g - 30 min x 4Lx0.47g/min.L = 93.6g

V = 320 L  30 min x 4 L/min = 200 L

c = 93.6 g / 200 L = 0.47 g/L

Therefore, the final salt concentration will be 0.47 g/min.