-
Ammonia gas was passed into water as shown below
a) Explain why the pH of solution is above 7
b) What is the use of inverted tunnel?
Date posted:
April 15, 2017
-
Ammonium nitrate was gently heated and the products collected as shown in the diagram below.
Describe one chemical and one physical method that can be used to identify gas G.
Date posted:
April 15, 2017
-
Study the flow chart below and answer the questions that follow.
(i) Name element M.
(ii) Why is it necessary to use excess air in step 4?
(iii) Identify gas Q.
(iv) Write an equation for the reaction in step 7
(v) Give one use of ammonia nitrate.
Date posted:
April 15, 2017
-
A student set up the apparatus shown below to prepare ammonia gas and react it with copper (II) sulphate solution
a) Identify solution V.
b) State the observations which were made in the beaker.
Date posted:
April 15, 2017
-
The flow chart below shows the industrial preparation of ammonia and the process used in the manufacture of some ammonium compounds. Study it and answer the questions that follow.
a) Give the name of the:
(i) Process in step 1.
(ii) Reaction that takes place in step 5.
b) State one other source of hydrogen gas apart from natural gas.
c) Explain why it is necessary to compress nitrogen and hydrogen in this process.
d) Write an equation for the reaction which takes place in step 6.
e) Name the catalyst and the reagents used in step 3.
f) Name compound Z 1
g) Give one commercial use of compound Z2
Date posted:
April 15, 2017
-
The diagram below represents a set up that was used to obtain dry nitrogen from air. Study it and answer the questions that follow:
(i) Name solid Q.
(ii) What is the purpose of sodium hydroxide?
(iii) Give the name of one impurity present in the nitrogen gas obtained.
(iv) Give a reason why liquid nitrogen is used for storage of semen for artificial insermination
Date posted:
April 15, 2017
-
The diagram below shows a set-up that can be used to obtain nitrogen gas in an experiment.
(i) Name liquid L.
(ii) What observation would be made in tube K after heating for some time?
(iii) Write an equation for the reaction that took place in tube K.
iv) At the end of experiment the pH of the water in the beaker was found to be about 10. Explain.
Date posted:
April 15, 2017
-
Figure 5 shows a flask fitted with a glass tube dipped into a beaker containing water at room temperature. The cork fixing the glass tube to the flask is airtight.
Use the information and the figure to answer the questions
a) State what is observed when ice-cold water is poured on the flask
b) Give a reason for the observation
Date posted:
April 13, 2017
-
Figure 1 shows a circuit diagram for controlling the temperature of a room
i) State and explain the purpose of the bimetallic strip.
ii) Describe how the circuit controls the temperature when the switch S is closed.
Date posted:
April 13, 2017
-
Brownian motion of smoke particles can be studied by using the apparatus shown in Figure 9. To observe the motion, some smoke is enclosed in the smoke cell and then observed through the microscope.
(a) Explain the role of the smoke particles, lens and microscope in the experiment.
(b) State and explain the nature of the observed motion of the smoke particles.
(c) State what will be observed about the motion of the smoke particles if the temperature surrounding the smoke cell is raised slightly
Date posted:
April 13, 2017
-
Figure 4 (i) shows a beaker filled with water. Some potassium permanganate was gently introduced at the bottom of the beaker at the position shown
Figure 4 (ii) shows the appearance of the liquid after about 30 minutes. Explain how this appearance was caused
Date posted:
April 13, 2017
-
Figure 3 shows two cylinders of different cross-sectional areas with a tube. The cylinder contain an incompressible fluid and are fitted with piston of cross-sectional areas 4 cm2 and 24 cm2
Opposing forces P and Q are applied to the pistons such that the pistons do not move. If the pressure on the smaller piston is 5 Ncm-2, determine force Q.
Date posted:
April 13, 2017
-
Figure 2 shows some air trapped by mercury in a glass tube. The tube is inverted in a dish containing mercury.
Given that the atmospheric pressure is 760 mmHg and the height of mercury column in the tube is 600 mm, determine the pressure of the air trapped in mmHg
Date posted:
April 13, 2017
-
Figure 14 shows a lift pump.
Explain why, when the piston is:
(i) pulled upwards, valve A opens while valve B closes.
(ii) Pushed downwards, valve A closes while valve B opens
Date posted:
April 13, 2017
-
Figure 3 shows the levels of two liquids A and B after some air has been sucked out of the tubes through the tap. Use this information and the figure to answer questions
State the reason for the rise in the levels of the liquids when air is sucked from the tubes
Date posted:
April 13, 2017
-
A can with a hole on the side is filled with water to a certain height. Water jets out as shown in figure 4 (a). A second identical can is filled with water to the same height and a block of wood floated on the water as shown in Figure 4 (b)
State the reason why the maximum distance of the jet, d2 is greater than d1
Date posted:
April 13, 2017
-
Figure 2 (a) and 2 (b) shows capillary tubes inserted in water and mercury respectively
It is observed that in the water the meniscus in the capillary tube is higher than the meniscus in the beaker, while in mercury the meniscus in the capillary tube is lower than the meniscus in the beaker. Explain these observations.
Date posted:
April 13, 2017
-
Figure 6 (a) and 6 (b) shows capillary tubes inserted in water and mercury respectively
It is observed that in water the meniscus in the capillary tube is higher than the meniscus in the beaker. While in mercury the meniscus in the capillary tube is lower than the meniscus in the beaker. Explain these observations
Date posted:
April 13, 2017
-
Figure 6 shows a small toy boat floating on water in a basin. X and Y are two points near the toy.
When a hot metal rod is dipped into the water at point X, the toy is observed to move towards Y. Explain this observation
Date posted:
April 13, 2017
-
Figure 8 shows water drops on two surfaces. In figure 8 (a) the glass surface is smeared with wax while in figure 8 (b) the glass surface is clean.
Explain the difference in the shapes of the drops
Date posted:
April 13, 2017
-
Figure 2 (a) shows the initial reading of burette used to measure the volume of oil. After 50 drops of the oil were run out, the final reading was as shown in figure 2 (b)
Determine the volume of one drop of oil
Date posted:
April 13, 2017
-
Figure 1 shows a measuring cylinder containing some water
Determine the reading on the measuring cylinder, after three drops of water each of volume 0.6 cm3 are added.
Date posted:
April 13, 2017
-
In an experiment to measure the density of a liquid, a student filled a burette with a liquid to the 0 cm 3 mark. Figure 1 shows a section of the burette showing the level of the liquid after 54.5 g of the liquid had been run out
Determine the density of the liquid
Date posted:
April 13, 2017
-
Figure 1 shows the change in volume of water in a measuring cylinder when an irregular solid is immersed in it.
Given that the mass of the solid is 567 g, determine the density of the solid in gcm-3
(Give your answer correct to 2 decimal places).
Date posted:
April 13, 2017
-
Figure 1 shows the reading on a burette after 55 drops of a liquid have been used.
If the initial reading was at zero mark, determine the volume of one drop.
Date posted:
April 13, 2017
-
Figure 1 shows a burette partly filed with a liquid. The burette was initially full to the mark 0. If the quantity of the liquid removed has a mass of 22 g, determine the density of the liquid
Date posted:
April 13, 2017
-
Fig. 1 shows a measuring cylinder, which contains water initially at level A. A solid of mass 11 g is immersed in the water, the level rises to B.
Determine the density of the solid. (Give your answer to 1 decimal point)
Date posted:
April 13, 2017
-
The figure below represents the set up that was used to crack an alkane
a) What was the purpose of the sand?
b) After some time, a colourless gas G collected in the test-tube. Describe a chemical test and observations that would be made in order to identify the class of compounds to which gas G belongs.
Date posted:
April 12, 2017
-
The set u below was used to prepare and collect ethane gas. Study it and answer the questions that follow.
i) Name the substance T.
ii) Give the property of ethane
Date posted:
April 12, 2017
-
a) The table below gives information about the major constituents of crude oil. Study it and answer the questions that follow.
i) Which one of the constituents of crude oil has molecules with the highest number of carbon atoms? Explain
ii) Name the process you would use to separate a mixture of petrol and diesel and explain how the separation takes place
iii) Explain why the constituent of crude oil have a range of boiling point.
Date posted:
April 12, 2017