3) An open system is one:

Select one:

a. Where energy is transferred with the environment, but not matter.

b. Where matter and energy are transferred with the environment.

c. Which is where the pressure is not maintained.

d. Where matter is transferred with the environment, but not energy.

e. Where no matter or energy is transferred with the environment.

4) An evaporator is used to concentrate an aqueous solution of sodium hydroxide, from 15% to x%, if 100 kg of NaOH enter and 65 kg are evaporated. The value of b is:

Select one:

a. 43

b. 65

c. 57

d. 35

e. 85