Law and Order: Reaction Unit
A reaction has the rate law: Rate = k[A]^1[B]^2.
What is the order with respect to A?
What is the order with respect to B?
What is the total order?
1
2
3
he reaction A + B -->C is found to be first-order with respect to A and first-order with respect to B. In a specific experiment, the initial rate of reaction was measured to be $1.2 x 10^-3 M/s when [A] = 0.20 M and [B] = 0.30M
k= 0.02 M^-1s^-1
You dissolve 15.0 g of urea CH4N2O in 200 g of water. Calculate the molality of the solution. (Molar mass of urea = 60.06 g/mol
1.25m
What is the boiling point of a 0.050m aqueous solution of Magnesium Chloride? (MgCl2) K=0.512
100.077C
The half life of an element is 14 days. What fraction of the sample will remain after 42 days?
1/8
The decomposition of ethyl chloride is a first-order reaction with a rate constant k of 1.60 x 10^-3s^-1. If the initial concentration is 0.50 M, what will the concentration be after 10 minutes?
0.19M
For the reaction 2X + Y --> Z, the reaction is found to be second-order with respect to X and zero-order with respect to Y.
In a laboratory experiment, the initial rate of the reaction was measured to be 8.0 x 10^-5 M/s when the concentration of X was 0.20 M and the concentration of Y was 0.50 M.
Calculate the value of the rate constant k and provide the correct units.
2.0 x 10^-3 M^-1s^-1
How would you prepare 150.0 g of an aqueous solution that is 4.0% Sodium Chloride (NaCl) by mass? What are the grams of NaCl? What are the grams of H2O?
6g NaCl, 144g H2O
What is the freezing point of a 0.20m aqueous solution of Sodium Phosphate? (Na3PO4) K=1.86
-1.48 C
A radioactive isotope has a half-life of 12.0 hours. If a laboratory starts with a 64.0 mg sample, how much of the isotope will remain after 48.0 hours?
4.0mg
The reaction 2A --> B is second-order with a rate constant k of 0.050 M^-1s^-1. If the initial concentration of A is 1.20 M, how long (in seconds) will it take for the concentration to decrease to 0.40 M?
33.3 seconds
Determine the rate law and rate constant for the reaction A+B→ C
(picture in notes)
rate=k[A]^2, k=0.048M
A chemist dissolves 40.0 g of sodium hydroxide NaOH in enough water to make a final solution volume of 250 mL. What is the molarity of the solution? (Molar mass of NaOH = 40.0 g/mol
4.00M
A solution is prepared by dissolving 35.0 g of hemoglobin (a non-electrolyte, i=1 in enough water to make 1.00 L of solution. If the osmotic pressure of the solution is found to be 0.0125 atm at 25 °C, what is the molar mass of hemoglobin? R=0.821
68493 g/mol
The rate constant k for the first-order decay of a certain substance is 0.0347 min^-1. Calculate the half-life of this substance.
20.0 min
The decomposition of ammonia NH3 on a hot platinum surface is a zero-order reaction with a rate constant k of 1.5 x 10^-4 M/s. If you start with an initial concentration of 0.0100 M, how many seconds will it take for the concentration to drop to 0.0025 M?
50 seconds
Determine the rate law and rate constant for the reaction 2NO + Cl2 → 2NOCl
(Picture of table in notes)
Rate = k[NO]^2[Cl2] k= 180
A 1.50 M aqueous solution of glucose C6H12O6 has a density of 1.10 g/mL. Calculate the molality m of this solution. (Molar mass of glucose = 180.16 g/mol
1.81m
An antifreeze solution is prepared by dissolving 222 g of ethylene glycol C2H6O2 in 500 g of water.
Calculate the molality of the solution.
Calculate the new freezing point of the solution.
Data: Molar mass of ethylene glycol = 62.07 g/mol; Kf for water = 1.86 °C/m; Freezing point of pure water = 0.00 °C
-13.31 C
The decomposition of element A is second order. If the initial concentration of A is 0.150mols/L and the initial reaction rate is 4.61x10^-4 mol/L. What is the rate constant for this reaction and what is the half life?
k=1.03L/molxs t=1485 seconds
Identify the equation that you need for this problem; it is not technically a rate law or order.
The rate constant for a first-order reaction is 4.60 x 10^-4 s^-1 at 350 K. If the activation energy Ea is 104 kJ/mol, calculate the rate constant at 400 K.
K2 = 0.040 s^-1
A radioactive isotope used in medical imaging decays via a first-order process. If the half-life t1/2 of the isotope is 6.0 hours, what is the rate constant k for this decay?
k = 0.1155 hr^-1
What are the mole fractions of ethylene glycol and water in a solution containing 1204g of ethylene glycol and 90g of water? (ethylene glycol = 62.07g/mol and water=18.02g/mol)
Ethylene glycol = 0.0385, water 0.9615
The solubility of pure nitrogen gas N2 in water at 25 °C and 1.00 atm is 6.8 x 10^-4 mol/L. If a diver breathes compressed air where the partial pressure of N2 is 4.50 atm, what is the new solubility of nitrogen in their blood? (Assume blood behaves like water for this calculation). Henry's Law Equation.
C= 3.06 x 10^-3 mol/L
The decomposition of a certain insecticide on a surface is a zero-order reaction with a rate constant (k) of 0.025 mol/Ls. If the initial concentration of the insecticide is 0.500M, calculate the half-life (t1/2) of the reaction.
10 seconds