ANSWER:
B. Mass and Speed
Why:
Because
Kinetic energy is proportional to the square of the velocity. If the velocity of an object doubles, the kinetic energy increases by a factor of four. Kinetic energy is proportional to the mass.
The only information in this problem that we are given with are the stoichiometric coefficients in the reaction, and the rate of disappearance of NH₃ as 0.05 M/s. The rate of disappearance always has a negative sign. The general formula would be:
Rate of Reaction = -(ΔNH₃/Δtime)(1/v), where v is the stoichiometric coefficient of NH₃ in the reaction
Substituting the values,
Rate of Reaction = -(0.05 M/s)(1/4) = <em>-0.0125 M/s</em>
Answer:
Explanation:
Magnesium when it oxidizes has a valence of 2.
Oxygen, when it mixes with something, has a valence of - 2
So Mg and O2 will form something, but what? The answer is MgO
Mg + O2 ===> MgO
To balance this equation, you need 2 Magnesiums on the right and 2 Oxygens also on the right. The left will need a two Magnesiums.
The balanced equation will be
2Mg + O2 ====> 2MgO
Answer:
The correct answer is <em>d. At equilibrium, the forward reaction and reverse reaction will have the same reaction rate.</em>
Explanation:
When a reaction begins, the reactants combine to form products. At the same time of product formation, the convertion of products into reactants also occur. The reaction reaches <em>chemical equilibrium </em>when the rate of forward reaction (the convertion of reactant into products) is equal to the rate of reverse reaction (the convertion of product into reactants). Upon this state, the concentration of reactants and products do not change in time (that does not mean that the concentration of reactants and products are equal, but that once the chemical equilibrium is reached, their concentrations at this point will not vary with the time because the forward and reverse reactions are occuring at the same velocity).
Answer:
D. It predicts whether or not a reaction will be spontaneous.
Explanation:
<em>What does Gibbs free energy (ΔG) predict?
.</em>
A. It predicts what the rate of the reaction will be. NO. ΔG is a thermodynamical parameter and it is not related to the kinetics of the reaction.
B. It predicts how high the activation energy is. NO. ΔG is a thermodynamical parameter and it is not related to the kinetics of the reaction.
C. It predicts if entropy will increase or decrease. NO. ΔG depends on the entropy but not the other way around.
D. It predicts whether or not a reaction will be spontaneous. YES. If ΔG < 0 the reaction is spontaneous and if ΔG > 0 the reaction is not spontaneous.
