Reactions
Ideal gasses
Solutions
Rates and equilibrium
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100
How many grams of CO2 are produced when 20.0 g of C2H5 burns completely?
58.5 g CO2
100
A 1.80 mol sample of gas is held at 78°F and a pressure of 2.50 atm.
What is the volume of the gas (in liters)?
17.6 L
100
Define electrolytes, and identify what makes them strong or weak.
Electrolytes are substances that break down into ions and are able to conduct electricity when dissolved.
Weak electrolytes do not dissolve completely when introduced into water.
Strong electrolytes dissolve completely when introduced into water.
100
Identify the following regions on the graph (one letter will not be used). Additionally, state if the reaction is endergonic or exergonic.
Reactants, products, activation energy, ∆H
a. reactants
b. activation energy
d. products
e. ∆H
This reaction is exergonic
(c is transition state, do not need to know)
100
The rate (speed) of a reaction is dependent solely on what?
The size of its activation energy (EA)
200
C3H8 + 5O2 → 3CO2 + 4H2O
How many grams of H2O form from 25.0 g of C3H8?
40.9 g H2O
200
A gas sample is collected at 755 mmHg and 240 mL at 22°C.
What is its molar amount?
0.00984 mol
200
At 20°C, the solubility of NaCl is 36 g/100 g H2O. If 90 g of NaCl is added to 200 g of water at 25°C, is the solution saturated or unsaturated?
What will it look like?
Saturated
Will have precipitation on the bottom
200
What are the three conditions that must be satisfied for a chemical reaction to occur?
a. Reactants must collide
b. Reactants must be oriented properly to break and form bonds
c. Collision must provide sufficient energy to activate the reaction
200
How does temperature affect the solubility of different types of solutes?
Higher temperature generally increases the solubility of solid solutes
Higher temperature generally decreases the solubility of gaseous solutes
300
N2(g) + 3H2(g) → 2NH3(g)
Determine the limiting reactant and how much NH3 will be produced from 14.0 g N2 and 3.0 g H2.
H2 is limiting
16.9 g of NH3 produced
300
A sample of carbon dioxide gas has a volume of 3.50 L at a pressure of 0.980 atm and a temperature of 45°C. What mass (in grams) of CO2 is present in the container?
5.76 g CO2
300
Write the products of the balanced chemical reaction and determine if there is a precipitate:
Na₂CO₃(aq) + CaCl₂(aq) → ?
Na2CO3(aq) + CaCl2(aq) → CaCO3(s) + 2NaCl(aq)
Rule 5: carbonates are insoluble except with group 1A and NH4+
300
State the three main ways to accelerate the rate of a reaction, as well as why they accelerate the reaction.
1. Increase the temperature
2. Increase reactant concentration
3. Add a catalyst
300
Draw what this reaction pathway would look like with the addition of a catalyst.
400
4Al + 3O2 → 2Al2O3
Find the limiting reactant and mass of Al₂O₃ produced from 10.0 g Al and 20.0 g O₂.
Al is limiting
18.9 g of Al2O3
400
A gas has an initial pressure of 0.875 atm, a volume of 650 mL, and a temperature of 22°C. The gas is heated to 65°C and compressed to 425 mL.
What is the final pressure?
P2 = 1.47 atm
400
How many grams of MgBr2 are needed to make 0.750 L of a 0.400 M solution?
55.2 g MgBr2
(molar mass = 184.11 g/mol)
400
Rank the following reactions from fastest to slowest, assuming they occur at the same temperature:
Reaction 1: ΔH = +15 kJ/mol, EA = +45 kJ/mol
Reaction 2: ΔH = –120 kJ/mol, EA = +30 kJ/mol
Reaction 3: ΔH = +70 kJ/mol, EA = +55 kJ/mol
Reaction 2 > reaction 1 > reaction 3
400
Identify whether the following gas law relationships are inverse or proportional:
a. Pressure vs. volume
b. Temperature vs. volume
c. Pressure vs. temperature
d. Volume vs. number of moles
a. Pressure vs. volume = inverse
b. Temperature vs. volume = proportional
c. Pressure vs. temperature = proportional
d. Volume vs. number of moles = proportional
500
Balance the following chemical equation:
Ba(OH)2 + H3PO4 → Ba3(PO4)2 + H2O
3Ba(OH)2 + 2H3PO4 → Ba3(PO4)2 + 6H2O
500
Which solution would yield the highest osmotic pressure?
a) BaSO4
b) NH4Cl
c) Mg(OH)2
d) Na3PO4
d) Na3PO4
a) BaSO4 (insoluble, yields 1 particle)
b) NH4Cl (soluble, yields 2 particles)
c) Mg(OH)2 (insoluble, yields 1 particle)
d) Na3PO4 (soluble, yields 4 particles)
500
This is a single reaction that has three different steps to it. Determine which step of this reaction (formation of transition state 1, 2, or 3) would be the slowest.
Formation of transition state 2 (largest activation energy).
500
Identify what would happen to a cell in each of the following conditions, as well as why:
Hypotonic solution
Hypertonic solution
Isotonic solution
Hypotonic solution = cell bursts (lysis)
Hypertonic solution = cell shrinks (crenation)
Isotonic solution = cell is unaffected