CHEM& 163 Unit 1 Review

Front

What is the activation energy for the forward reaction (E_a,fwd) if ΔH°_rxn = -35.4 kJ and E_a,rev = 83.9 kJ/mol?

Back

E_a,fwd = E_a,rev - ΔH°_rxn = 83.9 kJ/mol - (-35.4 kJ) = 48.5 kJ/mol.

Front

What is the initial reaction rate (in M/s) for Trial 5 if the options are 2.40 x 10^-3, 3.60 x 10^-3, 9.60 x 10^-3, or None of the above?

Back

The expected initial reaction rate for Trial 5 is None of the above.

Front

How much reactant is left after 363 years if the rate constant is 0.024 yr^-1?

Back

After 363 years, 42% of the original amount of reactant is left.

Front

What is the rate law for a reaction if the initial rate data suggests k[A]^2[B]^-1[C]^(1/2)?

Back

The rate law is k[A]^2[B]^-1[C]^(1/2).

Front

What is the energy released during the fission of a uranium-235 atom when bombarded by a neutron?

Back

The energy released is 2.777 x 10^-11 J.

Front

Define activation energy (E_a).

Back

Activation energy is the minimum energy required for a chemical reaction to occur.

Front

What is the difference between forward and reverse activation energy?

Back

Forward activation energy (E_a,fwd) is the energy needed for the forward reaction, while reverse activation energy (E_a,rev) is for the reverse reaction.

Front

Explain the concept of half-life in a decomposition reaction.

Back

Half-life is the time required for half of the reactant to decompose.

Front

What is a rate constant (k) in chemical kinetics?

Back

The rate constant (k) is a proportionality factor that relates the rate of a reaction to the concentration of reactants.

Front

What does a negative exponent in a rate law indicate?

Back

A negative exponent indicates that the concentration of that reactant decreases the rate of the reaction.