Question

Complete the changes in concentrations (or pressure, if requested) for each of the following reactions.

Short answer

a)

2SO3(g) (g)⇌ 2HO2(g)+ O2(g)
Change in concentration	\[ - 2x\]	\[ + 2x\]	\[ + x\]
Change in concentration	\[ - 0.125 \cdot 2 = - 0.250M\]	\[ + 0.125 \cdot 2 = + 0.250M\]	\[ + 0.125{\rm{M}}\]

b)

4NH3(g) + 3O2(g)⇌ 2N2O (g) 6H2 O(g)
Change in concentration	\[ + 4x\]	\[ + 3x\]	\[ - 2x\]	$ + 6x$
Change in concentration	\[\frac{{0.24M}}{3} \cdot 4 = + 0.32M\]	\[ + 0.24{\rm{M}}\]	\[ - \frac{{0.24M}}{3} \cdot 2 = - 0.16M\]	\[ - \frac{{0.24M}}{3} \cdot 6 = - 0.48M\]

c)

2CH4 (g)⇌ C2H2 (g) 3H2(g)
Change in concentration	\[ - 2x\]	\[ + x\]	\[ + 3x\]
Change in concentration	\[ - 25 \cdot 2 = - 50{\rm{\;torr\;}}\]	\[25{\rm{\;torr\;}}\]	\[ + 25{\rm{\;torr\;}} \cdot 3 = + 75{\rm{\;torr\;}}\]

d)

CH4 (g) + H2O(g)⇌ CO(g)
Change in concentration	\[ + x\]	\[ + x\]	\[ - x\]	$ - 3x$
Change in concentration	\[ + 5atm\]	\[5{\rm{atm}}\]	\[ - 5atm\]	\[ - 5{\rm{atm}} \cdot 3 = - 15{\rm{atm}}\]

e)

NH4Cl(s)⇌NH3(g) + HCl (g)
Change in concentration		\[ + x\]	\[ + x\]
Change in concentration		\[1.03 \cdot {10^{ - 4}}{\rm{M}}\]	\[ + 1.03 \cdot {10^{ - 4}}{\rm{M}}\]

f)

Ni (s) + 4CO (g)⇌Ni(CO)4 (g)
Change in concentration		\[ + 4x\]	\[ - x\]
Change in concentration		\[0.40atm\]	\[ - \frac{{0.40{\rm{atm}}}}{4} = - 0.10{\rm{atm}}\]

Step-by-step solution

Definition of change in concentration

The rate of a chemical reaction is defined as the rate of change in concentration of a reactant or product divided by its coefficient from the balanced equation.