Rates Of Reaction

Question 1

What is the equation for rate?

Answer 1

Rate = change in a measured quantity / time taken

Question 2

What is the equation for the rate of reaction?

Answer 2

Rate of reaction = 1 / average time

Question 3

What is the equation for average time?

Answer 3

Average time = time 1 + time 2 / 2

Question 4

What must happen for a reaction to take place between reacting particles?

Answer 4

Collide.

Have enough energy to react.

Question 5

What is activation energy?

Answer 5

Minimum amount of energy needed for chemical reaction to take place.

Question 6

How is rate of reaction affected when a solid is broken into smaller pieces or ground into a powder?

Answer 6

It’s surface area increases.
More particles exposed to reactant.
More successful collisions in given time.
Rate of reaction increases.

Question 7

What is the word equation for the complete combustion of carbon?

Answer 7

Carbon + Oxygen > Carbon dioxide

Question 8

What is the word equation for the incomplete combustion of carbon?

Answer 8

Carbon + Oxygen > Carbon monoxide

Question 9

What are the properties of carbon monoxide?

Answer 9

Toxic, colourless, odourless gas

Question 10

What are the physical properties of carbon dioxide?

Answer 10

Odourless
Colourless
Heavier than air
Slightly soluble in water
Does not support combustion
Is an acidic gas.

Question 11

What are the uses of carbon dioxide?

Answer 11

Fire extinguishers - does not aid combustion.
Carbonated drinks - soluble in water, dissolved under high pressure.
Dry ice.

Question 12

How does increasing concentration increase the rate of reaction?

Answer 12

More particles available for more successful collisions in a given time, increasing rate of reaction.

Question 13

What is the symbol equation for the reaction of carbon dioxide with water?

Answer 13

CO2 + H2O > H2CO3

Question 14

What is the method for the test for carbon dioxide gas?

Answer 14

Carbon dioxide is bubbled through limewater, chemical reaction occurs and insoluble calcium carbonate is formed.
Solution turns from colourless to milky/cloudy.

Question 15

What is the word equation for the test for carbon dioxide gas?

Answer 15

Carbon hydroxide + Carbon dioxide > Calcium carbonate + Water

Question 16

What is the word equation for the test for carbon dioxide in excess CO2?

Answer 16

Calcium hydroxide + Water + Carbon dioxide > Calcium hydrogen carbonate

Question 17

What happens when excess carbon dioxide is bubbled through limewater?

Answer 17

Milky/cloudy solution turns back to colourless.

Question 18

What is the percentage of carbon dioxide in the atmosphere of Earth?

Answer 18

0.03% -0.04% CO2 in air.

Question 19

What is the affect of increasing temperature on the rate of reaction?

Answer 19

As temperature increases, particles gain energy and move faster.
Leading to more successful collisions in given period of time.
Rate of reaction increases.

Question 20

What is a catalyst?

Answer 20

Substance which speeds up rate of chemical reaction without itself undergoing permanent chemical change.

Question 21

What do catalysts provide in a reaction?

Answer 21

Alternative pathway with lower activation energy (Ea).

Question 22

What is an example of a reaction that uses a catalyst?

Answer 22

Hydrogen peroxide > Water + Oxygen

2H2O2 > 2H2O +O2

Question 23

What is an example of a catalyst which is used to increase the rate of reaction?

Answer 23

Manganese (IV) oxide.

Question 24

What is the test for oxygen gas?

Answer 24

Oxygen gas will relight a glowing splint.

Question 25

What are the physical properties of oxygen?

Answer 25

Colourless Odourless Gas Same weight as air Slightly soluble in water Supports combustion.

Question 26

What are some uses of oxygen?

Answer 26

Breathing apparatus. Welding. Rocket engines. Steel making.

Question 27

What are the reactions of oxygen?

Answer 27

Magnesium Copper Iron Sulfur Carbon

Question 28

What are the observation for the reaction of oxygen with magnesium?

Answer 28

Grey magnesium burns with bright white flame producing white ash of magnesium oxide. Solid produced is basic oxide.

Question 29

What are the observation for the reaction of oxygen with copper?

Answer 29

Red-brown solid glows red when heated and blue-green flame is produced. Black layer of basic copper oxide is formed.

Question 30

What are the observation for the reaction of oxygen with iron?

Answer 30

Grey solid burns with orange sparks. Black basic oxide is formed.

Question 31

What are the observation for the reaction of oxygen with sulfur?

Answer 31

Yellow solid burns with blue flame, bad smell is produced and melts into red liquid. Colourless, pungent gas of acidic sulfur oxide is formed.

Question 32

What are the observation for the reaction of oxygen with carbon?

Answer 32

Carbon monoxide produced in limited supply. Carbon dioxide produced in plentiful supply. Black carbon burns with orange sparks producing acidic colourless gas.

Question 33

What are the physical properties of hydrogen?

Answer 33

Colourless, odourless gas Insoluble in water Less dense than air Neutral

Question 34

What is the test for hydrogen gas?

Answer 34

When lighted splint is held to test tube of hydrogen it will burn with squeaky pop.

Question 35

What are some of the uses of hydrogen?

Answer 35

Meteorological balloons - hydrogen less dense than air. Hardening oils - increases melting point of an oil. Potential clean fuels - does not produce carbon dioxide gas during use.

Question 36

What are the reactions of Hydrogen?

Answer 36

Oxygen Copper oxide Nitrogen in Haber process

Question 37

What are the observation for the reaction of hydrogen with oxygen?

Answer 37

Oxygen is reduced as it gains hydrogen. Hydrogen is reducing agent as it caused reduction to take place.

Question 38

What is the word equation for the reaction of hydrogen with oxygen?

Answer 38

Hydrogen + Oxygen > Water

Question 39

What are the observation for the reaction of hydrogen with copper oxide?

Answer 39

Hydrogen acts as reducing agent and reduces copper oxide to copper.

Question 40

What is the word equation for the reaction of hydrogen with copper oxide?

Answer 40

Copper oxide + Hydrogen > Copper + Water

Question 41

What are the observation for the reaction of hydrogen with nitrogen in the Haber process?

Answer 41

Nitrogen is very unreactive elemtn and reacts with very few other elements. It reacts with hydrogen to produce ammonia in Haber process.

Question 42

What is the word equation for the reaction of hydrogen with nitrogen in the Haber process?

Answer 42

Nitrogen + Hydrogen > Ammonia