Chemistry Two Exam Three

2BrNO(g)<->2NO(g)+Br2(g)

What could we do to push the reaction to the right?

• Add BrNo

  Remove NO

• Add NO

  Remove BrNo

CaCO3(s)<->CaO(g)+CO2(g)

What can we do to shift it left?

• Add more CO2

• Remove some CO2

• Add more CaCO3

Answer explanation

The solid CaCO3 won't effect it because it's a solid so it is not included in the equilibrium expression. (we leave out (s) and (l) compounds in a equilibrium expression)

2KClO3(s)<->2KCl(s)+3O2(g)

What change in volume is needed to move it to the right?

• no change

• increase the volume

• decrease the volume

Answer explanation

When we want to decrease pressure we need to increase the volume

2SO2(g)+O2(g)<->2SO3(g)

Delta H= -253 kJ

list five things we can do to move the reaction to the left?

• Add SO3(g)

  Remove SO2(g)

  Remove O2 (g)

  Increase the volume

  Increase the heat

• Remove SO3(g)

  Add SO2(g)

  Add O2 (g)

  Decrease the volume

  Decrease the heat

Consider an exothermic reaction:

2NO(g)+Cl2(g)<->2NOCl(g)

Which change causes a reaction mixture at equilibrium to shift right?

• Adding NOCl to the reaction mixture

• Increasing the volume of the reaction vessel at constant temperature

• Increasing the temperature of the reaction vessel

• None of the above

• A

• B

• C

HF= 1.0x10^-4=Ka

HCHO3 Ka=1.8x10^-7

HC2H3O2 Ka=1.6x10^-5

HI

Write them in order from the weakest to the strongest

• HI, HCHO3, HC2H3O2, HF,

• HC2H3O2, HCHO3, HF, HI

• HCHO3, HC2H3O2, HF, HI

Answer explanation

HI is the only strong acid in the bunch (refer to the six strong acids in your notes). The lower the ionization constant (Ka) the weaker the acid

[HCl]= 0.20 M

[HNO3]= 0.33 M

[H3O^+]=???

• 53 M

• 0.48 M

• 0.53 M

• 48 M

Answer explanation

Both are strong acids so we can add the two concentrations together to get the answer.

• A

• B

• C

HPO4^2- is the conjugate base of what?

• H2PO4^-

• H3PO4

• HPO4^+