CP Chemistry Final Review KEY

CP Chemistry Final Review KEY(SHOW YOUR WORK FOR CALCULATIONS)

Chapter 14:

#1 = see textbook

#2 = see textbook

#5 = the volume would need to increase by a factor of 4

#7 = Boyle’s Law: P1V1 = P2V2 = 6.48 L

#9 = Charles’s Law: V1/T1 = V2/T2 = * make sure to change temp. to Kelvin = 3.39 L

#11 = Gay-Lussac’s Law: P1/T1 = P2/T2 = * make sure to change temp. to K = 2.58 kPa

#15 = volume will decrease as pressure increases

#16 = as temp. increases, volume will increase

#17 = as temp. increases, pressure will increase

#23 =Ideal Gas Law (PV = nRT) *make sure all of the units match the units in R = 0.0821 (L x atm/mol x K) CALCULATION = 251 mol

#25 = an expression that carries the variable n

#34 = gases with lower molar masses diffuse and effuse faster than gases with higher molar masses

Chapter 15 and 16

#2 = ice has a honeycomb-like structure of hydrogen-bonded water molecules

#3 = chemical composition of the solute and solvent determine whether a substance will dissolve, particle size of the solute determine how fast a substance will dissolve

#4 = grams of solute per 100 g of solvent

#16 = if the number of moles and the volume of a solution is known, its molarity is determined by dividing the moles of solute by the volume of the solution

#19 = 1 sig fig = 0.6 M

#20 = 0.010 mol

#21 = 7.50 mL

#24 =the 2 we studied and that you have to know are: freezing point depression and boiling point elevation

#29 = molality (m) = moles solute/kg solvent = 13 g

#33 =Freezing Point Depression: ΔTf = Kf x m, Kf = 1.86 °C/m

ΔTf = Kf x m = 1.86 °C/m x 1.11m = 2.06 °C

Water normally freezes at 0 °C. Therefore, 0 °C - 2.06 °C = -2.06 °C

#35 = Boiling Point Elevation of an ionic compound (REMEMBER THE LAB WE DID WITH NaCl): ΔTb = Kb x m x i (where i = the number of ions in solution. CaCl2 = 3 particles), Kb = 0.52 °C/m

ΔTf = Kf x m x i = 0.52 °C/m x 0.89 m x 3 = 1.4°C

Water normally boils at 100 °C. Therefore, 100 °C + 1.4 °C = 101.4 °C

Chapter 17

#10 = 2.36 x 10-1 J/g°C

#13 = we did something similar in lab: q = mCΔT = 25.0 mL is the same as 25.0 g for water...

q = mCΔT = (25.0 g) x (4.184 J/g°C) x (1.4°C) = 150 J

Chapter 18

#6 = a) favors reactants, b) favors reactants, c) favors products, d) favors products

#49 = they are equal

#51 a =

#51 b = same method you did for 51a

#52 = a) highly favorable b) favorable c) unfavorable

Chapter 19

#3 = see textbook

#4 = see textbook

#5 = see textbook

# 7 a = see textbook

#7 b = HNO3 + H2O  H3O+ + NO3-; HNO3 is the hydrogen-ion donor (ACID), its conjugate base is NO3-. H2O is the hydrogen-ion acceptor (BASE), its conjugate acids is H3O+

#9 =DO THE MATH!!!!

a and c) solve for pH, then use the pH scale to determine if it is acidic or basic

b and d) look at the ion!!! It is OH-. Solve for pOH, then pH (pH + pOH = 14), then determine if it is acidic or basic

#10 = problem gives you [OH-] which means you can solve for pOH. Then solve for pH and then the [H+] and determine if the solution is acidic, basic, or neutral

#11 = a) 4, b) 2.8

#13 = a) 1 x 10-5M, b) 1.479 x 10-13M

#15 =solve for pOH first because you have the [OH-]. Then solve for the pH knowing that pH + pOH = 14

#24 = “strong” completely dissociates, “weak” only partially dissociates

#35 = neutralization

Chapter 25

#1 = an unstable nucleus releases energy by emitting radiation during radioactive decay

#2 = see textbook or notes

#3 = which part is it in the atom? Think about it…

#4 = atomic number is the number of protons. Alpha decay makes the atomic number decrease by 2 since an alpha particle is a helium nucleus (atomic number 2). Beta decay makes the atomic number increase by 1. Gamma radiation does not change the atomic number.

#5 = mass number is the number of protons and neutrons in the nucleus of an atom. Alpha decay make the atomic mass decrease by 4 since an alpha particle is a helium nucleus (atomic mass of 4). Beta decay and gamma radiation do not change the atomic mass number.

#6 = gamma

#10 = 50% of the sample remains after one half-life, 25% remains after 2 half-lives.

#12 b =

#12 c =

#12 d = same type of example as 12 c

#13 =a) 10 g b) 5 g