[amoleanatre]

Please, if anyone knows the steps to figuring out these problems, let me know! It's pretty urgent, and I can't seem to find similar questions from past tests or homework... thanks!

MULTI-STEP

1. Consider: NaI + KOH ---> NaOH + KI

Determine the # of kilograms of KI made if 15 mL NaI react with excess KOH. The Density of the NaI is 1.33 g/mL.

2. If 7.84 x 10^24 atoms of calcium hydroxide react with sodium fluoride, determine the # of grams of calcium fluoride that can be made.

3. Determine the amt. of heat released for the reaction below if KOH reacts with excess HCl:
          KOH + HCl -----> KCl + H2O + 12.4 kJ

SOLUTIONS

(note-K_b for water= 0.52º C/m
k_f for water= 1.86º C/m
m is molality= mol solute/ kg solvent )

4. How many milliliters of a 50% (by mass) solution, with a density of 2 grams per milliliter, are required to make 500.0 mL of a 2 M HNO3 solution?

5. Calculate the # of grams of glycerol, C3H5(OH)3, that must be dissolved in 520 g of water to raise the boiling point to 102ºC.

6. Determine the k_x of a pure substance if you have 250 mL of the substance and have 1.35 moles of solid dissolved in it. The boiling point of the pure substance is 88ºC, but the boiling point with the solid dissolved into it is 112ºC.

[Bakegaku]

Try looking through the equations you have learned so far in chemistry and see if any are relevant to the variables you are given and the ones you need to find.  We can't do the whole problem out for you.

[Alpha-Omega]

HINT:

MULTI-STEP

1. Consider: NaI + KOH ---> NaOH + KI

Determine the # of kilograms of KI made if 15 mL NaI react with excess KOH. The Density of the NaI is 1.33 g/mL.

Species react mole to mole not gram to gram.

You are told you have a volume of NaI (15 mL) that has a density of 1.33 g/mL. 
So you use this data to determine your moles:

(15 mL NaI) x (1.33 g/mL NaI) = 19.95 g

You know now that 19.95 g of NaI were reacted.
Now find the moles: