Which of the following sets of processes uses a gas that ignites with a "pop" sound when a lighted splint is passed through it?

1. Balloon filling, welding and diving 
2. Hardening oil, balloon filling and welding
3. Hardening oil, balloon filling and diving
4. Fueling rocket, diving and welding
5. Balloon filling, fueling rocket and diving

What is the best way of preparing hydrogen gas in the laboratory?

1. By reacting strong metals and dilute acids.
2. By reacting metals and acids.
3. By reacting moderate metals and concentrated acids.
4. By reacting moderate metals and dilute acids. 
5. By reacting strong metals and strong acids.

  The only metal which does not react with dilute hydrochloric acid is

1. Magnesium
2. Aluminum
3. Copper
4. Zinc
5. Sodium.

Why hydrogen gas is not a constituent of air?

1. Because of being water soluble
2. Because of being denser than air
3. Because of being very light
4. Because of being highly flammable.

  Why is hydrogen gas collected over water and by upward delivery method?

1. It is insoluble in water and less denser than air.
2. It is soluble in water and denser than air.
3. It is insoluble in water and denser than air.
4. It is soluble in water and less denser than air.
5. It is soluble in both water and air.

 (b) Which property enables the use of hydrogen gas in: 

(i)     Filling weather balloons?

……………… ………………… ……… ……… 

(ii)  Production of oxy – hydrogen flame?

………… ………… ………………………… ….

Suppose that two gas jars; one containing gas "A" and another one containing gas "B" are made available to you. Gas "A" is used in hardening of margarine whereas gas "B" is used by mountain climbers.

(a)What tests will you conduct to identify each of the two gases?

(b)Give two physical properties and three chemical properties that can be used to distinguish gas "A" from gas "B". 

6.(a) During preparation of Hydrogen gas by the reaction between dilute Hydrochloric acid and Zinc granules, the granules slowly dissolve in acid to form solution X. 

(i) Name solution X .........

(ii) Write the chemical formula of X . . . . . . 

(b) How can hydrogen gas be tested?

(c) Mention four (4) chemical properties of hydrogen gas.

(d) List three (3) uses of Hydrogen gas.

9.   The following figure shows a set-up used to prepare gas

(a)  Identify gas Q

(b)Identify other two chemical substances that could be used in the laboratory to prepare gas Q if zinc is not present.

(c) State two physical properties of gas Q.

(d) State two chemical properties of gas Q.

9.When dilute hydrochloric acid is reacted with zinc metal, gas Z is formed.

(a)Identify the name of gas Z.

(b)Mention four physical properties of gas Z. State two uses of gas Z.

(a) Study the experiment diagram below and answer the questions that follow.

(i)What happens to the copper (Il) oxide during the experiment?

(ii)What happens to the two pieces of cobalt paper? (iii) Write a word equation for the reaction.

(b) Mention four chemical properties of hydrogen gas.

9.Gas "L" has the following properties: it is highly flammable, readily combines with other elements, readily reacts with other chemical substances and is a strong reducing agent.

Name the gas L

(b)      What is the method used to collect gas in the laboratory? Give a reason.

Give four uses of gas L

2. Match each item in List A with a correct response in List B by writing its letter bellow the number of the corresponding item in the table provided.

The laboratory technician planned to conduct an experiment for the preparation of gas Y. The following set of apparatuses was used: Flat-bottomed flask, thistle funnel, delivery tube, beehive shelf and gas jars. Also pieces of zinc metal and dilute hydrochloric acid were used.

1. Identify gas Y
2. What apparatus is missing in the set provided?
3. Draw a well labeled diagram for the preparation of gas Y in the laboratory
4. Write the word equation for the laboratory preparation of gas Y.

(b) Hydrogen peroxide breaks down slowly to form water and oxygen; the reaction can be speed up by using a catalyst.

1. How does the catalyst speed up the rate of reaction?
2. Name a possible catalyst that can be used to speed up the reaction.
3. Show that the catalyst always remains unchanged at the end of the reaction.

9. (a) Name two elements which are expected to show similar chemical reaction with magnesium. What is the basis for your choice?