chem

Question 1

Exothermic Reaction

Answer 1

Gives out energy to the surroundings usually in the form of heat

Question 2

Endothermic Reaction

Answer 2

Takes energy from its surroundings in the form of heat, showing a fall in temp

Question 3

reaction profiles?

Answer 3

are diagrams that show the relative energies of the reactants and products in a reaction, it also shows how energy changes over time

Question 4

Activation energy, also known as…

Answer 4

Ea

Question 5

Activation energy?

Answer 5

minimum amount of energy the reactants need to collide with each other and react.

Question 6

Exothermic reactions in reaction profiles?

Answer 6

products are at a lower energy than the reactants

Question 7

Endothermic reactions in reaction profiles?

Answer 7

products are at a higher energy than the reactants because the energy is taken in.

Question 8

Enthalpy change in Exothermic Reactions?

Answer 8

Negative

Question 9

Enthalpy change in Endothermic?

Answer 9

Postitive

Question 10

Enthalpy Change?

Answer 10

amount of heat evolved or absorbed in a reaction carried out at constant pressure.

Question 11

Rate of reaction dependencies?

Answer 11

1) temp
2) concentration of a solution or pressure of gas
3) Surface area, changes are dependant of the size of the solid
4) Presence of a catalyst

Question 12

what does more collisions do to the rate of reactions?

Answer 12

It gets it higher

Question 13

name 4 things that increase the rate of reactions?

Answer 13

1) higher temp
2) higher concentration/pressure
3) Catalysts
4) Smaller solid particles combining more Surface Area

Question 14

reactions only happen if…

Answer 14

particles collide with enough energy

Question 15

In gas, what does it mean by increasing the pressure?

Answer 15

getting the particles to be more crowded, frequency of collisions will increase.

Question 16

What happens if a solution is made more concentrated

Answer 16

It means there are more particles of reactant in the same volume

Question 17

What will increase when a solid is breaking into smaller pieces?

Answer 17

Surface area

Question 18

A catalyst is a substance which increases the rate of a reaction without…

Answer 18

being chemically changed or used up in the reaction.

Question 19

will a catalyst change the products of a reaction?

Answer 19

No, so the reaction equation will stay the same.
Because it isn’t used up, you can use catalysts for large amounts of reactants.

Question 20

Do Catalysts work with all reactions?

Answer 20

No.

Question 21

How do catalysts work?

Answer 21

They decrease the activation energy for a reaction to occur, making it quicker. They do this by providing an alternative reaction pathway that has a lower activation energy

Question 22

What does a catalyst do to the particles?

Answer 22

more of the particles will have the minimum amount of energy needed for a reaction to occur when particles collide.

Question 23

What substances make great fuels?

Answer 23

Hydrocarbons.

Question 24

Is burning a combustion reaction?

Answer 24

Yes.

Question 25

What energy does fuel release when burning?

Answer 25

Heat.

Question 26

Why do Hydrocarbons make great fuels

Answer 26

When you burn them in oxygen, they give out lots of heat energy. This is a very exothermic reaction.

Question 27

Combustion Equation?

Answer 27

hydrocarbon + oxygen --> carbon dioxide + water

Question 28

What is the process called when there isn't enough oxygen around for a complete combustion reaction.

Answer 28

Incomplete combustion.

Question 29

The products of incomplete combustion contain ___________ than carbon dioxide.

Answer 29

less oxygen.

Question 30

What does an incomplete combustion produce?

Answer 30

carbon monoxide and Soot.

Question 31

What is produced when crude oil is burnt?

Answer 31

Sulfur dioxide, nitrogen oxides. (these MAY be produced).

Question 32

How are nitrogen oxides created?

Answer 32

When the temp is high enough for the nitrogen and oxygen in the air to react.

Question 33

Nitrogen oxides include... and ...

Answer 33

nitrogen monoxide (NO) and nitrogen dioxide (NO2).

Question 34

What forms when sulfur dioxide and nitrogen oxides mix with water vapor in the clouds?

Answer 34

dilute sulfuric acid and nitric acid.

Question 35

What will you get if you heat a metal carbonate?

Answer 35

carbon dioxide and metal oxide.

Question 36

Thermal decomposition?

Answer 36

a substance breaks down into simpler substances when heated.

Question 37

Copper Carbonate(II) thermal decomposition and equation?

Answer 37

Copper(II) carbonate is a green powder that will easily decompose to form carbon dioxide and copper(II) oxide when you heat it. Equation: CuCO3 (s) --> CuO (s) + CO2(g) To do the experiment, heat copper(II) carbonate then collect the gas that's given off in a test tube. The gas that is collected can then be tested to see if it is CO2 using limewater.

Question 38

First 5 Hydrocarbons

Answer 38

1) Methane 2) Ethane 3) Propane 4) Butane 5) Pentane

Question 39

First 5 Hydrocarbons

Answer 39

1) Methane 2) Ethane 3) Propane 4) Butane 5) Pentane