Chapter 9
Solve the ideal gas law equation for pressure.
solid to gas
Entropy describes
universal disorder / spontaneity
As the activation energy for a reaction increases, the speed of a reaction
Decreases
Identify the Bronsted-Lowry acid and base in the following reaction.
NH4+ + H2O <-> NH3 + H3O+
NH4 is the acid (loses a proton)
H2O is the base (gains a proton)
Total pressure = [partial pressure of gas A] + [partial pressure of gas B] + ...
the vapor pressure = external pressure of the atmosphere
Ionic solutes are more soluble in nonpolar or polar solvents?
Polar
Which of the following decreases the reaction rate?
More than one correct answer
I. Decrease concentration of the reactants
II. Increase temperature
III. Adding a catalyst
IV. Increasing the surface area (if reactant is a solid)
II
Identify the Bronsted-Lowry conjugate acid and conjugate base in the following reaction.
H2CO3 + H2O <-> HCO3- + H3O+
H2O acts as a base here, so H3O+ will be the conjugate acid.
Bonus!
Bonus!
Which of these statements is false?
I. Solids have a fixed shape.
II. Gases fill their container.
III. There is little free space between solid particles.
IV. Gas particles have the lowest kinetic energy of any of the phases.
V. Liquids have a fixed volume and have more kinetic energy than solids.
IV
Kinetic energy = molecular movement of the particles
Higher KE = higher temperature
Gas > liquid > solid in terms of kinetic energy.
A
Like dissolves like.
C (s) + H2O (g) > CO(g) + H2(g)
K = [products]/[reactants]
Only gases and aqueous solutions included.
K = [CO][H2] / [H2O]
Which of the following is NOT a strong acid?
I. Hydrochloric acid
II. Nitric acid
III. Chloric acid
IV. Phosphoric acid
V. Perchloric acid
IV
R = 0.08206 L*atm/mol*K
pv/NR = T
T = ~29.2 degrees Celsius
What intermolecular forces are present?
Dipole-dipole forces (polar bond between carbon and nitrogen)
Hydrogen bonding (between nitrogen and hydrogen)
moles solute = 22.6 g sodium chloride / 58.44 g (molar mass) = 0.387 moles
L solution = 25 dL / 10 = 2.5 L
0.387 moles / 2.5 L = 0.1548 M
AB (s) <-> A+ (aq) + B- (aq)
What will happen if you remove B- through the addition of an acid? Which way will the reaction shift?
As products are removed, the system will shift to "make up" for that difference and will produce more products. The system will shift to the right.
You are giving a solution of 0.006 M H2SO4 Calculate the pH and pOH of this solution.
Is this solution acidic or basic?
-log[H3O+] = pH
pH = -log[0.006] = 2.22
pOH = 14 - pH = 14 - 2.22 = 11.78
Acidic (low pH/high pOH)
A sample of hydrogen gas has a volume of 7.49 L at a pressure of 22 atmospheres and a temperature of 305.2 degrees Kelvin. What volume of gaseous water is produced by the following reaction at 398.2 degrees Kelvin and 0.975 atmospheres, if all the hydrogen gas reacts with iron(III) oxide?
Reaction: Fe2O3(s) + 3 H2(g) -> 2 Fe(s) + 3 H2O (g)
R = 0.08206 L*atm/mol*K
Use pv=nRT for H2 to solve for moles (n) of H2
Mole ratio of H2 to H2O to solve for moles of H2O
Use pv=nRT again, but this time you are solving for V of water
V = 221 L
Express your answer in kJ and determine if the process is endothermic or exothermic.
Convert 3 kg to g = 3,000 g
q=MCT -> q=(3000)(4.184)(32-86)q = -677.2 kJ
Our negative q-value indicates that this process is exothermic.
M1V1 / V2 = M2
M2 = 0.359 M
In an experiment, gaseous hydroiodic acid dissociates into hydrogen gas and iodine gas.
hydroiodic acid = 0.704 M
hydrogen gas = 0.180 M
iodine gas = 0.550 M
Set up an equilibrium expression, determine the value of the equilibrium constant given the concentrations, and interpret the value (are products or reactants favored?).
Plug in values.
[0.180][0.550] / [0.704]2
K = 0.200
K < 1 (reactants are favored)
Is our blood acidic or basic?
[H3O+] = 10-pH
[H3O+] = 10-7.35 = 4.47 x 10-8 M
[OH-] = 10-pOH
pOH = 14 - 7.35 = 6.65 = 10-6.65 = 2.24 x 10-7 M
Our blood is just slightly basic. Our body responds to any changes in our pH through the carbonate/bicarbonate buffering system.