1.

Homogeneous Mixture	Solvent	Solute(s)
a. 18 K gold (24 K is pure)	Gold	Copper, silver etc
b. Air	Nitrogen	Oxygen, argon, CO2, H2O
c. ocean water	water	Na^+, Cl^-, HCO3^-1, Mg^+2, Br^-1
d. 7up	water	Sugar, CO2, flavours

2. Why does salt seem to disappear as it dissolves in water?

Water breaks up the crystal and separates the ions.

3. What part of the water molecule faces a dissolved Mg⁺² ion? Draw it.

The oxygen faces it

4. Complete and balance the following ionic equations:

a. KBr_(s) à K⁺¹_(aq) + Br^-1_(aq)

b. CaCl_2(s) à Ca⁺²_(aq) + 2 Cl^-1_(aq)

c. (NH₄)₂S_(s) à 2NH₄⁺¹_(aq) + S^-2_(aq)

d. Na₂CO_3(s) à 2 Na⁺¹_(aq) + CO₃^-2_(aq)

e. AlPO_4(s) à Al⁺³_(aq) + PO₄^-3_(aq)

f. AlCl_3(s) à Al⁺³_(aq) + 3 Cl^-1_(aq)

g. AgNO_3(s) à Ag⁺¹_(aq) + NO₃^-1_(aq)

h. ZnCl_2(s) à Zn⁺²_(aq) + 2 Cl^-1_(aq)

i. KOH_(s) à K⁺¹_(aq) + OH^-1_(aq)

j. HF_(s) à H⁺¹_(aq) + F^-1_(aq)

k. RbBr_(s) à Rb⁺¹_(aq) + Br^-1_(aq)

l. Ca(NO₃)_2(s)à Ca⁺²_(aq) + NO₃^-1_(aq)

m. Al₂S_3(s) à Al⁺³_(aq) + S^-2_(aq)

4. If 4.0 grams of Na₃N dissolved in water, what mass of ions would be created in solution?

Answer: 4.0 grams ( mass is conserved!)

5. (430 only) How many moles of sodium would appear in solution for every gram of sodium nitride (Na₃N) that dissolved?

Na₃N_(s) à 3 Na⁺¹_(aq) + N^-3_(aq) Yeap! That’s right. We need to write a balanced equation before ink and mistakes leak out of our pens.

1.0 g(mole/83g/mole) = 0.0120 moles of Na₃N_(s)

Examine ratio: there will be 3(0.0120) = 0.036 moles of Na⁺¹ in solution