High school chemistry, help need ASAP! (5 questions)

1: What is the mole fraction of KCl in a 0.20 molal solution of KCl? (molar mass of KCl = 75 g; molar mass of water = 18 g)

#2: What is the rate of a first-order reaction that has a reactant concentration of 0.1M and a rate constant of 0.1/s?

#3: What is the hydrogen-ion concentration if the acid dissociation constant is 0.000 001 and the acid concentration is 0.01M?

#4: What is the total increase in oxidation number for the atom that is oxidized in the following redox reaction?

#5: The vapor pressure of 10 mL of ethanol at 20 deg C is 5.85 kPa. What is the vapor pressure of 20 mL of ethanol at the same temperature?

mole fraction is like asking what is the % KCl in the solution
0.2m KCl = 0.2moles KCl in 1000g H2O
0.2moles KCl and 1000g/18g/mole = 55.56moles H2O
mole fraction KCl = 0.2moles / (55.56moles water + 0.2moles KCl) = 0.0036

2. rate = k[A]
rate = 0.1/sec x [0.1M] = 0.01M/s

3. Ka = 1x10^-6
is the acid mono-, di-, tri-protic?
Ka = [H+][A-] / [HA]
1x10^-6 = (x)(x) / 0.01 - x
x^2 + 1x10^-6x - 1x10^-8 = 0
x = [H+] = 9.95x10^-5M

4. what reaction?

5. p1v1 = p2v2
plug in the numbers