Atank 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.

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.

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.