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The flow chart below shows the Haber process in the large scale manufacture of Ammonia gas. Use it to answer the questions that follow.
Describe how nitrogen is obtained from air on a large scale.
(a) (i) Name one source of hydrogen gas used as a raw material in the above process.
(ii) Name chamber A.
(iii) Write an equation for the reaction taking place in the catalytic chamber.
(iv) In the Haber process optimum temperature of 5000C and 200 atmospheres of pressure are used to get optimum yield of
Ammonia. Why can’t lower temperatures and higher pressure be used?
(b) Give two reasons why finely divided iron is the commonly used catalyst.
(c) State and explain the observation made when dry ammonia gas is passed over heated copper (II) Oxide
in a combustion tube.
(d) Give two uses of ammonia gas.
Date posted:
March 27, 2019
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A radio repairer wishes to use an ammeter to detect a faulty diode. With the aid of a circuit diagram describe how he will go about this task.
Date posted:
March 27, 2019
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Study the flow chart below and answer the questions that follow.
(i) Name the process taking place in step (I).
(ii) Describe chemical test that can be carried out to show the identity of organic compound A.
(iii) Give the name of the following:
I. A:
II. B:
(iv) Give the structural formulae of substance C.
(v) Name the type of reaction that occurs in:
I. Step IV
II. Step VI:
(vi) Give the reagent and the condition necessary for step VI.
Reagent:
Condition:
(b) Give the systematic names of the following compounds:
I. CH2CHCHCH2CH3
II. CH C C H3
Date posted:
March 27, 2019
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During Olympics, urine sample of five short distance runners were taken and tested for the presence of two illegal steroids by paper chromatography. Methanol was used as the solvent. A chromatogram from the test appeared as shown below. Study the chromatogram and answer the questions that follow.
(a) Which of the two steroids is most likely to be more soluble in methanol? Give a reason.
(b) Identify the athletes that tested positive for the illegal steroids.
Date posted:
March 27, 2019
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The diagram shows a photocell in action
i) The photocell is either evacuated or filled with an inert gas at low pressure. Give one reason for this
ii) What is the function of the resistor R in the circuit?
iii) State one reason for using a particular radiation such as ultraviolet for a given photocell.
iv) Explain how the set-up shown in the diagram may be used as an automatic switching device for a burglar alarm.
Date posted:
March 27, 2019
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Light of frequency 5.5x 1014 HZ is made to strike a surface whose work function is 2.5ev. Show that photoelectric effect will not take place. H= 6.6 X 1034Js
Date posted:
March 27, 2019
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Some salts may be classified as double salts or basic salts. Trona with the formula Na2CO3.NaHCO3 is an example of a double salt. An example of a basic salt is basic magnesium carbonate with formula MgCO3.Mg(OH)2.
(a) What is meant by a double salt?
(b) Write equations of reactions that occur when dilute hydrochloric acid is reacted with:
(i) Trona
(ii) Basic magnesium carbonate.
Date posted:
March 27, 2019
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State the purpose of cooling fins in the X-ray tube.
Date posted:
March 27, 2019
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A gaseous compound consists of 86% carbon and 14% hydrogen by mass. At s.t.p. 3.2dm3 of the compound had a mass of 6g. Calculate its molecular formula.(1 mole of a gas at s.t.p. = 22.4dm3)
Date posted:
March 27, 2019
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An experiment was set up using chlorine water as shown below.
(i) Identify gas X.
(ii) Write an equation for the production of gas X.
Date posted:
March 27, 2019
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The set-up below shows the catalytic oxidation of ammonia in the laboratory.
(a) Identify the brown fumes observed at the mouth of the conical flask.
(b) Write down the equations of the reactions representing
(i) Catalytic oxidation of ammonia
(ii) The formation of the brown fumes.
Date posted:
March 27, 2019
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State three reasons why air is considered to be a mixture but not a compound.
Date posted:
March 27, 2019
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Below is a set-up of apparatus used to prepare hydrogen gas in the laboratory. Study it and answer the questions that follow.
(a) Write a chemical equation for the two reactions taking place in he above set-up.
(b) State the chemical test for hydrogen gas.
Date posted:
March 27, 2019
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A uniform plank of wood is pivoted at its centre. A block of wood of mass 2kg is balanced by a mass of 1.5 placed 30cm from the pivot as shown.
i) Calculate the distance X
ii) When the same block of wood is partially immersed in water, the 1.5kg mass need to be placed at 20cm from the pivot to balance it. Calculate the weight of the water displaced.
Date posted:
March 27, 2019
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A right angled solid of dimensions 0.02m by 0.02m by 0.2m and density 2,700kg/m3 is supported inside kerosene of density 800kg/m3 by a thread which is attached to a spring balance. The long side is vertical and the upper surface is 0.1m below the surface of the kerosene.
i) Calculate the force due to the liquid on the lower upper surface of the solid.
ii) Calculate the up thrust and determine the reading on the spring balance.
Date posted:
March 27, 2019
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Define an Escarpment with a diagram.
Date posted:
March 27, 2019
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A mass of 120 g half immersed in water displaced a volume of 20 cm3. Calculate the density of the object
Date posted:
March 27, 2019
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With an aid of a diagram define a ridge.
Date posted:
March 27, 2019
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Determine the density of glass that weighs 0.5N in air and 0.3N in water.
Date posted:
March 27, 2019
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In an experiment to study properties of carbon, a small amount of charcoal is placed in a boiling tube. 5.0cm3 of concentrated nitric acid is added. The mixture is then heated.
(a) What observations are made?
(b) Write an equation for the reaction that took place in the boiling tube.
(c) What property of carbon is shown in this reaction?
Date posted:
March 27, 2019
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A body moving with uniform angular velocity found to have covered an angular distance 170 radians in t seconds. Thirteen seconds later it is found to have covered a total angular distance of 300 radians. Determine t
Date posted:
March 27, 2019
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Describe the guidelines that assist system auditors detect and deter fraud occurrences in an organization
Date posted:
March 27, 2019
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The graph below shows the amount of calcium carbonate and calcium chloride varying with time in the reaction.
(a) Which curve shows the amount of calcium chloride varying with time?
(b) Explain why the two curves become horizontal after a given period of time.
Date posted:
March 27, 2019
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The table below gives the solubility of potassium bromide and potassium sulphate at 00C and 400C.
When an aqueous mixture containing 60g of potassium bromide and 7g potassium sulphate in 100g of water at 800C was cooled to 00C, some crystals were formed.
(a) Identify the crystals.
(b) Determine the mass of the crystals.
Date posted:
March 27, 2019
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Describe with the aid of labeled diagram an experiment to determine the focal length of the lens when provided with the following; an illuminated object, a convex lens, a lens holder, a plane mirror and a metre rule.
Date posted:
March 27, 2019
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Name three gaseous constituents involved in gaseous exchange in plants.
Date posted:
March 26, 2019
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Explain why water logging of the soil may lead to death in plants.
Date posted:
March 26, 2019
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In an experiment to determine the specific latent heat of vaporization of water, steam at 1000c was passed into water contained in a well-lagged copper calorimeter. The following measurements were made:
Mass of calorimeter = 50g
Initial mass of water = 70g
Final mass of calorimeter + water + condensed steam = 123g
Final temperature of mixture = 300C
(Specific heat capacity of water = 4200 J kg -1K and specific heat capacity for copper = 390 J kg -1 K-1)
Determine the:
i) Mass of condensed steam
ii) Heat gained by the calorimeter and water
iii) Given that L is the specific latent heat of evaporation of steam
I. Write an expression for the heat given out by steam
II. Determine the value of L.
Date posted:
March 26, 2019
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The structure below represents two cleansing agents A and B. Which cleansing agent would be suitable for washing in water containing calcium chloride? Give a reason.
Date posted:
March 26, 2019
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An immersion heater rated 90W is placed in a liquid of mass 2kg. When the heater is switched on for 15 minutes, the temperature of the liquid rises from 200C to 300C. Determine the specific heat of the liquid.
Date posted:
March 26, 2019