Answer:
by providing an alternative pathway with a lower activation energy
Explanation:
Cataysts are the substances that neither consumed nor produced during a chemical reaction, but increase the rate of the reaction.
So, catalysts remain chemically unchnaged after the completion of the reaction.
For a reaction to occur, reactants molecule must collide and successful collisions lead to product formation.
A certain minimum amount of energy is required for successful collision. This minimum amounr of energy is called activation energy.
One way to increase speed of reaction is to provide energy to the reactants and other way to increase speed is to provide alternate pathway with lower activation energy.
Catalyst increases a rate of reaction by providing an alternate pathway with lower activation energy.
Therefore, the correct option is option b 'by providing an alternative pathway with a lower activation energy'
I will have to go with carbon monoxide
Answer:
65.4%
Explanation:
The redox reaction is a 1:1:1 reaction because the reagents suffer a double displacement reaction, and the substance that is substituted have the same charge (H+ and Br-), thus, we first need to know which of the reagents is the limiting.
Let's test the 4-nitrobenzaldehyde as the limiting. The mass needed for sodium borohydride (m) is the mass given of 4-nitrobenzaldehyde multiplied by the stoichiometric mass of sodium borohydride divided by the stoichiometric mass of 4-nitrobenzaldehyde. The stoichiometric mass is the number of moles in the stoichiometric representation (1:1:1) multiplied by the molar mass, so:
m = (4.13 * 37.83*1)/(151.12*1)
m = 1.034 g
So, the mass needed of the other reagent is larger than the mass that was given, so, it will be the limiting, and the stoichiometric calculus must be done with it.
The mass of the product that was expected is then:
m = (0.700*153.14*1)/(37.83*1)
m = 2.83 g
The percent yield is the mass that was formed divided by the expected mass, and then multiplied by 100%:
%yield = (1.85/2.83)*100%
%yield = 65.4%
D. Has a uniform composition and is only able to be separated by chemical means.
The answer is B. molality
