exam 2

Question 1

when writing a total ionic equation, which compounds do we separate?

Answer 1

Soluble ionic salts
Strong acids
Strong bases

Question 2

when writing a total ionic equation, which compounds do we keep together?

Answer 2

weak acids/bases
insoluble salts
pure liquid/gases
molecular compounds

Question 3

Which are the strong acids?

Answer 3

HCl
HBr
HI
HNO3
H2SO4
HClO4

Question 4

Which are the strong bases?

Answer 4

LiOH
KOH
NaOH
Ca(OH)2
Ba(OH)2

Question 5

When doing calculations for dissulotiobns, q(rxn)=

Answer 5

-q(diss)

Question 6

Using the standard heats of formation that follow, calculate the standard enthalpy change for X.
Formula=

Answer 6

Question 7

1 cal in J

Answer 7

1 cal=4.184J

Question 8

1 BTU in J

Answer 8

1055.06 J

Question 9

Make a diagram showing the relationship between gas, liquid, and solid phase changes

Answer 9

Question 10

4 types of reactions

Answer 10

• combination
• decomposition
• displacement
• oxidation-reduction

Question 11

What are three forms of double displacement reactions?

Answer 11

• Precipitation reaction
  forms an insoluble solid
• Acid-Base/Neutralization reaction
  forms water
• Gas-forming reaction
  forms a gas

Question 12

What are some solvents?

Answer 12

• Aqueous (water)
• Tincture (alcohol)
• Amalgam (mercury)
• Organic (polar and non-polar)

Question 13

What are the four ways compounds can behave in water?

Answer 13

1. dissolve and completely break up into its ions (100% dissociation).
   Ions are hydrated. (If other solvent: solvated)
2. dissolve and only a small
   amount break up into its ions (<1-5%)
3. Dissolves but does not dissociate
4. Does not dissolve. Does not dissociate

Question 14

A compound dissolve and completely break up into its ions. The ions are…

Answer 14

Hydrated

If other solvent: solvated

Question 15

What is a strong electrolyte?

Answer 15

A substance that dissociates completely in water.

• soluble ionic salts (and insoluble)
• strong acids
• strong bases

Question 16

What are nonelectrolytes?

Answer 16

A substance that dissolves in water but does not conduct electricity.

Covalent/Molecular compounds

Question 17

What is a weak electrolyte?

Answer 17

A substance that dissolves in water but only partially dissociate.
<1-5% ionized

• weak acids
• weak bases
• tap water (has trace minerals)

Question 18

To be an electrolyte, the compound must…

Answer 18

be soluble AND form ions.

Question 19

How do you know if a compound is soluable?

Answer 19

• Molecular compounds: it must be polar
• Ionic compounds: use the solubility rules
• All acids are soluable, most bases

Question 20

Which ions are always soluable?

Answer 20

Question 21

A reaction between an acid and a base forms…

Answer 21

salt + water

Question 22

M1V1=M2V2

What does it stand for?

Answer 22

M is Molarity (moles/liter)
V is volume

make sure that V is in the same unit on both sides

Question 23

Electrolyte status of

Acids and bases
Ionic compounds
Molecular compounds

Answer 23

Strong acids+bases - strong electrolytes

Weak acids+bases - weak electrolytes

Soluble+insoluble ionic compounds - strong electrolytes

Polar+non-polar molecular compounds - nonelectrolytes

Question 24

Solubility status of

Acids and bases
Ionic compounds
Molecular compounds

Answer 24

Strong+weak acids+bases - soluble

Soluble ionic compounds - soluble

insoluble ionic compounds - insoluble

Polar molecular compounds - soluble

non-polar molecular compounds - insoluble

Question 25

weak acids I'm less familiar with?

Answer 25

Acetic acid CH3COOH Ammonium NH4^+

Question 26

weak bases

Answer 26

Acetate CH3COO- Ammonia NH3 Carbonate CO3^2- Oxalate C2O4^- Sulfite SO3^2- Sulfide S^2- Phosphate PO4^3- Cyanide CN^- Fluoride F- Nitrite NO2^- Hypochlorite ClO^-