According to Boyle's law, volume is inversely proportional to pressure. thus P=k/V
Therefore PV=k
P1V1=P2V2
In the question above,
P1=3.67atm
P2=1.94atm
V1=2.22L
V2=?
Thus substituting for the values in the gas equation;
3.67atm*2.22L=1.94atm*V2
V2=3.67atm*2.22L/1.94atm
=4.21L
Answer: Iron gains electrons mean It is reduced
Explanation:
Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reactions occur simultaneously.
Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.

Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.

Thus iron gains electrons mean It is reduced
C.
This is because the number of products is greater than the number of reactants.
Answer:
The answer to your question is Cr₂O₃ + 3Mg ⇒ 2Cr + 3MgO
Explanation:
Data
Unbalanced chemical reaction
Cr₂O₃ + Mg ⇒ Cr + MgO
Reactants Elements Products
2 Cr 1
3 O 1
1 Mg 1
Balanced chemical reaction
Cr₂O₃ + 3Mg ⇒ 2Cr + 3MgO
Reactants Elements Products
2 Cr 2
3 O 3
3 Mg 3
Now the reaction is balanced