Kinetics
The decomposition of a pestecide compound applied to crops results in a first-order reaction with 56 days as its half-life. What is the rate constant?
56 day^-1
0.012 day^-1
81 day^-1
0.018 day^-1
Given four substances with nearly identical molecular weights, which would have the highest boiling point based on its dominant intermolecular forces?
Nitrogen gas (N2), due to London dispersion forces.
Methane (CH4), due to London dispersion forces.
Carbon monoxide (CO), due to dipole-dipole interactions.
Hydrogen fluoride (HF), due to hydrogen bonding.
What does the reaction order n describe in a rate law?
The duration of the chemical reaction
The level of complexity of the chemical reaction
The velocity at which molecules collide
The effect of molecule concentration on the reaction rate
Which of the following factors would most significantly affect the rate-determining step of a complex reaction mechanism?
Concentration of products in the final step.
Activation energy of the fastest elementary step.
Overall enthalpy change of the reaction.
Activation energy of the slowest elementary step.
How do you calculate moles from molarity and volume?
Multiply molarity by volume
Divide density by molarity
Multiply volume by density
Add mass to volume
Which term describes the amount of solute dissolved in a given volume of solvent?
Molarity
Solubility
Molality
Concentration
Qual equação representa corretamente o cálculo da concentração molar de uma solução?
Peso molecular do soluto / peso total da solução.
Mols de soluto / volume da solução em litros.
Volume total da mistura / número de mols do produto formado.
Número de partÃculas / volume da solução em mililitros.

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What happens to the half-life of a second-order reaction when the initial concentration of reactants is doubled?
The half-life doubles.
The half-life increases by four times.
The half-life remains unchanged.
The half-life decreases by half.
What is plotted for a first order reaction? What is the lines slope?
ln[A] vs time, -k
ln[A] vs time, k
[A] vs time, -k
1/[A] vs time, k
What happens to the half-life of a second-order reaction when its initial concentration is halved?
Halves.
Remains constant.
Doubles.
Quadruples.