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3 years ago

Which statement best describes the way a catalyst works?

Chemistry

1 answer:

bogdanovich [222]3 years ago

6 0

Answer: E. It decreases the value of Eact.

Explanation:

Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.

A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and more molecules convert to products.

The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.

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Which statement is a valid conclusion about the activation energy of the reverse reaction if the forward reaction is exothermic?

babunello [35]

Answer:

e) The activation energy of the reverse reaction is greater than that of the forward reaction.

Explanation:

Activation energy is the minimum amount of energy that is required by the reactants to start a reaction.
An exothermic reaction is a reaction that releases heat energy to the surrounding while an endothermic reactions is a reaction that absorbs heat from the surrounding.
In reversible reactions, when the forward reaction is exothermic it means the reverse reaction will be endothermic, therefore the reverse reaction will have a higher activation energy than the forward reaction. The activation energy of the reverse reaction will be the sum of the enthalpy and the activation energy of the forward reaction.

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3 years ago

Consider two processes: sublimation of I2(s) and melting of I2(s) (Note: the latter process can occur at the same temperature bu

AVprozaik [17]

Answer:

positive

Explanation:

Entropy -

In a system, the randomness is measured by the term entropy .

Randomness basically refers as a form of energy that can not be used for any work.

The change in entropy is given by amount heat per change in temperature.

When solid is converted to gas entropy increases,

As the molecules in solid state are tightly packed and has more force of attraction between the molecules, but as it is converted to gas, the force of attraction between the molecule decreases and hence entropy increases.

So,

The particles of the substance , if are tightly held by strong force of attraction will decrease the entropy ,

And

If the particles are loosely held , the entropy will increase , i.e. , positive entropy .

Similar with solid converting to liquid , the entropy will increases , i.e. , positive entropy .

Hence ,

The correct sign of entropy for both the process is positive .

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3 years ago

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Suppose your teacher ask you to separate a mixture of sand and water.Which of the following merhods would u use:distillation fil

MrRa [10]

Answer:

Filtration

Explanation:

Filtration would be best because the sand particles would be trapped in the filter paper and the water would go through so the mixture would be separated

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2 years ago