Please Answer Chemical change and energy Questions!?

Question

TRUE or FALSE:

1. The production of methane gas occours very rarely in nature.

2. Gas formation is a phase not a chemical change.

3. Every chemical reaction involves energy in some form.

4. Every chemical bond does contain energy.

5. Chemical reactions are studied by the energy contained in the productsin comparison to the reactants.

6. Chemical changes must involve the breaking and making of chemical bonds.

Answer 1

1.) False: it occurs often.

2.) That is borderline: gas can be produced during a chemical change .
Example: CaH2 (s)+ 2H2O (l) --> Ca(OH)2 (s) + 2H2 (gas)

However, boiling water into steam is a physical change. No compounds form and no elements become free radicals.

3.) True

4.) True: eventhough it could be just sitting there, it has potential energy.

5.) True,..and then some. It is not only the energy of the products, but the quantity, quality as well as the actual procedure.

6.) True.

Answer 2

1. The production of methane gas occours very rarely in nature.
False
2. Gas formation is a phase not a chemical change.
False
3. Every chemical reaction involves energy in some form.
True
4. Every chemical bond does contain energy.
True
5. Chemical reactions are studied by the energy contained in the productsin comparison to the reactants.
True
6. Chemical changes must involve the breaking and making of chemical bonds.
True

Answer 3

1. false, it occurs very frequently
2. depends. if a liquid is heated so that it becomes a gas (vapour) it is a phase. if a reaction occurs to produce a gas then it is a chemical change.
3. true, although the overall energy change can be neutral
4. true
5. true. it is one way they are studied
6. true. breaking bonds requires energy, making new ones gives out energy.

Answer 4

1) false, there are bacteria that make this
2) false,formation means something had to happen involving a chemical change
3)True,, but not a very good question, fuzzy
4)True, bonds have electrons and electrons have energy
5)True
6)guess true, maybe there are exceptions to this

Answer 5

Gasoline combined with air for rapid oxidation. This is harnessed by the pistons to move the car. The watermelon dropping loses its potential energy in exchange for gaining momentum. The wind blowing by it on the way down may cause it to loose a little thermal but not much.

Answer 6

The first 2 are false. The rest are true.

Answer 7

Not sure
F
T
T
T