2. Explain the effect of:

a. Adding or removing gas to a constant volume. What happens to the pressure? Is this a

direct or indirect relationshin?

The pressure increases when you add gas and decreases when you remove gas. This a direct relationship.

Explanation:

The pressure comes from the collisions of the particles with the walls of the container.

If there are more particles, there are more collisions. The pressure increases.

If there are fewer particles, there are fewer collisions. The pressure decreases.

The pressure is directly proportional to the number of particles.

p ∝ n

h let me think about that

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g