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In petrol chemical industries, long chain alkanes are broken down in to simpler substances in a process called cracking
a) Why is cracking necessary?
b) State the two conditions required in cracking
c) Draw the structure of 1-chloro-2, 2-dimethylpropane
Date posted:
October 17, 2019
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An object 10cm high is placed 30cm in front of a concave mirror. The image is 45cm in front of the mirror. Find its magnification and size of the image.
Date posted:
October 17, 2019
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In an attempt to make a magnet, a student used the double stroke method as shown below.
State the polarities at the ends A and B
Date posted:
October 17, 2019
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500g of water at 200C is mixed with 200g of water at 550C. Find the final temperature of the mixture.
Date posted:
October 17, 2019
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A car moving initially at 10m/s decelerates at 2.5m/s2
Determine:
i)I) Its velocity after 1.5seconds.
II)The distance travelled in 1.5 seconds.
III)The time taken for the car to stop.
ii)Sketch the velocity – time graph for the motion of the car up to the time the car stopped.
iii)From the graph determine the distance the car travelled before stopping.
Date posted:
October 17, 2019
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But-z-ene undergoes hydrogenation according to the equation given below
CH3CH = CHCH3(g) + H2(g)----->CH3CH2CH2CH3(g)
Name the product formed when but-z-ene reacts with hydrogen gas
Date posted:
October 17, 2019
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The diagram below shows a six’s maximum/ minimum thermometer.
)What is the thermometric liquid in this thermometer?
b)Why is it necessary for the vapour in bulb B to be saturated?
c)Explain how the thermometer indicates maximum and minimum temperature.
d)Indicate on the diagram the two points where the reading of the temperature shown by the
thermometer can be made.
Date posted:
October 17, 2019
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Use the figure below to answer the questions that follow
i)What pressure is acting on point A?
ii)What is the value of pressure difference in the instrument reading?
iii)If the atmospheric pressure is 760mm of mercury, what is the value of gas pressure?
Date posted:
October 17, 2019
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Use the flow chart below to answer the questions that follow:
(a) What observation would be made in process K?
(b) Name another conditions necessary for process J to take place
(c) Give the name of substance V
Date posted:
October 17, 2019
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The figure below shows an incompressible fluid moving through a tube of varied cross- sectional area. If the area of the small tube is 0.05m2, calculate the diameter of the large tube in cm.
Date posted:
October 17, 2019
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The figure below shows two light sheets of paper arranged as shown.
Explain the observation made when air is blown at the same speed and time at points A and B.
Date posted:
October 17, 2019
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Distinguish between streamline and turbulent flow.
Date posted:
October 17, 2019
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A bullet of mass 20g moving with a velocity of 30m/s penetrates a sand bag and it’s brought to rest in 0.05 seconds. Find the average retarding force of the sand.
Date posted:
October 17, 2019
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During welding of cracked railway lines by thermite 12.0g of oxide of iron is reduced by aluminium to 8.40g of iron. Determine the empirical formula of the oxide(Fe= 56.0, O= 16.0)
Date posted:
October 17, 2019
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A tightly fitted bottle cork will be easier to remove if the bottle is warmed.
Explain this using kinetic and thermal property of matter.
Date posted:
October 17, 2019
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State one way of increasing sensitivity of mercury in glass thermometer.
Date posted:
October 17, 2019
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1.6g of magnesium metal is reacted with excess hydrochloric acid. Calculate the volume
of hydrogen gas produced (Molar gas volume at stp = 22.4dm3 Mg=24)
Date posted:
October 17, 2019
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A mercury barometer reads 75cmHg at the base of Mt.Kenya. Assuming that the height of
the mountain is 1088m and the average density of air is 1.25kg/m3. What is the reading of the
barometer at the top of the mountain? (Take density of mercury is 13.6g/cm3.)
Date posted:
October 17, 2019
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Before using a vernier calipers to measure diameter of a steel ball, a student confirmed that it had a zero error of -0.03cm. The figure below shows the vernier calipers scale when in use.
State the correct diameter of the steel ball.
Date posted:
October 17, 2019
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10.08g of ethanedioic acid (H2C2O4.xH2O) crystals were dissolved in water and made to 1dm3 solution. 25.0cm3 of this solution was completely neutralized by 20cm3 of 0.2M
sodium hydroxide solution.
Calculate
i) Molarity of the acid
ii)the value of x in H2C2O4xH2O acid
Date posted:
October 17, 2019
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State four qualities of a good feed store.
Date posted:
October 17, 2019
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Campers GAZ cylinder contains about 1.12dm3 of butane measured at 0o and 1atm. Given that 25% of heat is lost, what is the maximum volume of water at room temperature which can be boiled to 100oC in order to make some coffee?
Date posted:
October 17, 2019
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State two reasons why drenching alone is not an effective method of controlling liver fluke.
Date posted:
October 17, 2019
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Distinguish between opening and closing valuation.
Date posted:
October 17, 2019
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The following information was extracted from the farm records of Mukulu farm, as at 31/12/2014.
Prepare profit and loss account for Mukulu farm using the above information.
Date posted:
October 17, 2019
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An organic compound P contains 68.9% carbon, 13.5% hydrogen and 21.6% oxygen.
The relative formula mass of p is 74. Determine its molecular formula. [C=12, H=1, 0=16]
Date posted:
October 17, 2019
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State two factors which may determine the size of a cut off drain.
Date posted:
October 17, 2019
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In a reaction 20cm3 of 0.1 M Sodium Carbonate completely reacted with 13cm3 of dilute sulphuric acid. Find the molarity of the sulphuric acid used.
Date posted:
October 17, 2019
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Calculate the number of water molecules when 34.8g Na2CO3 xH2O is heated and 15.9g of anhydrous Na2CO3 obtained (H=1, O=16, Na= 23, C = 12)
Date posted:
October 17, 2019
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Give two practices that are commonly used in hardening seedlings in a kales nursery.
Date posted:
October 17, 2019