Which statement correctly describes a chemical reaction?

1)Reactants come out of a reaction.
2)Energy is always released.
3)Bonds between atoms break and new bonds form.
4)Products go into a reaction.

Question

Which statement correctly describes a chemical reaction?

1)Reactants come out of a reaction.
2)Energy is always released.
3)Bonds between atoms break and new bonds form.
4)Products go into a reaction.

matt101 · Answer

3 is the correct answer.

Reactants go in and products go out, so 1 and 4 are both wrong. Reactions can absorb or release energy, depending on the specific reaction, so 2 is wrong as well.

anonymous · Answer

thanks and can you help me with one more please? matt101

matt101 · Answer

Sure

anonymous · Answer

A researcher is designing a laboratory experiment to determine whether the inorganic substance A affects the rate of a reaction between two colored liquids, X and Y. When the reaction is complete, the liquid is clear. The reaction between X and Y is similar to one used by manufacturers to produce certain chemicals in factories.
Which method would best answer his question about reaction rate and what will he find out about substance A?



First, he should measure the final temperature of the liquid when X and Y react without substance A. Then, he should measure the final temperature when he adds substance A to X and Y. He will find out if substance A is a catalyst.

First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalyst.

First, he should measure the final temperature of the liquid when X and Y react without substance A. Then, he should measure the final temperature when he adds substance A to X and Y. He will find out if substance A is an enzyme.

First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is an enzyme.

matt101 · Answer

The second option is the only one that makes any sense. A catalyst speeds up the rate of the reaction, so if the solution becomes clear faster in the presence of A, it could be a catalyst.

anonymous · Answer

ok thank you!!