Methyl orange, HMO, is a common acid-base indicator. In solution it ionizes according to the equation:

HMO(aq) ⇌ H+(aq) + MO−(aq)

red yellow

What color will the solution turn if H+ is added and why?

A) Red. H+ concentration increases. Reaction moves to the right.

B) Yellow. H+ concentration increases. Reaction moves to the right.

C) Yellow. H+ concentration decreases. Reaction moves to the left.

D) Yellow. H+ concentration increases. Reaction moves to the left.

E) Red. H+ concentration decreases. Reaction moves to the left.

F) Red. H+ concentration decreases. Reaction moves to the right.

G) Yellow. H+ concentration decreases. Reaction moves to the right.

H) Red. H+ concentration increases. Reaction moves to the left.

2.

Methyl orange, HMO, is a common acid-base indicator. In solution it ionizes according to the equation:

HMO(aq) ⇌ H+(aq) + MO−(aq)

red yellow

What color will the solution turn if OH- is added and why?

A) Yellow. H+ concentration decreases. Reaction moves to the right.

B) Yellow. H+ concentration increases. Reaction moves to the left.

C) Yellow. H+ concentration increases. Reaction moves to the right.

D) Red. H+ concentration decreases. Reaction moves to the left.

E) Red. H+ concentration decreases. Reaction moves to the right.

F) Yellow. H+ concentration decreases. Reaction moves to the left.

G) Red. H+ concentration increases. Reaction moves to the left.

H) Red. H+ concentration increases. Reaction moves to the right.

3.

Magnesium hydroxide is only very slightly soluble in water. The reaction by which it goes into solution is:

Mg(OH)2(s) ⇌ Mg2+(aq) + 2 OH−(aq)

What will happen if OH- is added to the solution and why?

A) Solid remains. OH- concentration increases. Reaction moves to the right.

B) Solid dissolves. OH- concentration decreases. Reaction moves to the right.

C) Solid dissolves. OH- concentration increases. Reaction moves to the right.

D) Solid remains. OH- concentration increases. Reaction moves to the left.

E) Solid remains. OH- concentration decreases. Reaction moves to the right.

F) Solid dissolves. OH- concentration decreases. Reaction moves to the left.

G) Solid remains. OH- concentration decreases. Reaction moves to the left.

H) Solid dissolves. OH- concentration increases. Reaction moves to the left.

4.

Magnesium hydroxide is only very slightly soluble in water. The reaction by which it goes into solution is:

Mg(OH)2(s) ⇌ Mg2+(aq) + 2 OH−(aq)

What will happen if H+ is added to the solution and why?

A) Solid dissolves. OH- concentration increases. Reaction moves to the left.

B) Solid remains. OH- concentration increases. Reaction moves to the right.

C) Solid dissolves. OH- concentration decreases. Reaction moves to the left.

D) Solid remains. OH- concentration increases. Reaction moves to the left.

E) Solid remains. OH- concentration decreases. Reaction moves to the right.

F) Solid dissolves. OH- concentration increases. Reaction moves to the right.

G) Solid dissolves. OH- concentration decreases. Reaction moves to the right.

H) Solid remains. OH- concentration decreases. Reaction moves to the left.