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State the observations made when buton-l-ol reacts with:-
(i) Acidified potassium dichromate (VI) solution
(ii) Potassium metal
Date posted:
October 22, 2019
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The set-up below was used to prepare ethyne gas
(i) Identify solid E
(ii) Complete the diagram to show how the gas can be collected
(iii) Write an equation to show how the gas is formed
(iv) Complete the equation below: )
C2H2 + 2I2---------------->
(v) What is the role of sand in the experiment?
Date posted:
October 18, 2019
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The diagram below represents a large-scale fractional distillation plant used to separate the components A, B, C and D in a mixture
The components have the following average relative molecular masses not necessarily in that
order; 282, 184, 44 and 128.
(i) What is the physical state of B at the position marked Q?
(ii) Which component has an average relative molecular mass of 128? Explain
(iii) State with a reason whether C is pure or impure
(iv) Explain how the mixture is separated into its components
(v) Name two naturally occurring mixtures that are separated using this process
Date posted:
October 18, 2019
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Give the open structures of:-
(i) 3-chlorohex-l-yne
(ii) CH3OH
Date posted:
October 18, 2019
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10cm3 of methane (CH4) gas is exploded with 150cm3 of air containing 20% oxygen and 80% nitrogen. The products were allowed to cool to room temperature. What will be the total volume of the gases at the end of the reaction?
Date posted:
October 17, 2019
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Polymerisation of ethene takes place as shown in the equation below:
Name the type of polymerisation undergone by ethene in the reaction above
Date posted:
October 17, 2019
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In a reaction an alcohol K was converted to hex-1-ene
Name reagent and condition necessary for the reaction above to occur
Date posted:
October 17, 2019
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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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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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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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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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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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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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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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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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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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3.52g of Carbon (IV) Oxide and 1.40g of water are produced when a mass of a hydrocarbon is completely burnt in oxygen. Determine the empirical formula of the hydrocarbon;
(H = 1 , C= 12, O = 16)
Date posted:
October 17, 2019
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Calculate the volume of oxygen gas used during the burning of magnesium (O = 16, molar gas volume = 24,000cm3 at room temperature)
Date posted:
October 17, 2019
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How many chloride ions are present in 1.7g of magnesium chloride crystals?
(Avogadro’s constant = 6.0 x 1023, Mg = 24, Cl = 35.5)
Date posted:
October 17, 2019
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When 1.675g of hydrated sodium carbonate was reacted with excess hydrochloric acid,
the volume carbon (IV) oxide gas obtained at room temperature and pressure was 150cm3).
Calculate the number of moles of water of crystallization in one mole of hydrated sodium
carbonate:- (Na=23, H =1, C=12, O=16, MGV at R.T.P = 24000cm3)
Date posted:
October 17, 2019
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The equation of the formation of iron (III) chloride is
2Fe(s) + 3Cl2(g)------>2FeCl3
Calculate the volume of chlorine which will react with iron to form 0.5g of Iron (III) chloride.
(Fe = 56 Cl=35.5). Molar gas volume at 298K = 24dm3)
Date posted:
October 17, 2019
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In a filtration experiment 25cm3 of a solution of Sodium Hydroxide containing 8g per
litre was required for complete neutralization of 0.245g of a dibasic acid. Calculate
the relative molecular mass of the acid (Na = 23.0, O = 16, H= 1)
Date posted:
October 17, 2019
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In an experiment magnesium ribbon was heated in air. The product formed was found to be heavier than the original ribbon. Potassium manganate (VII) was on the other hand, heated in air and product formed was found to be lighter. Explain the differences on the observation made
Date posted:
October 17, 2019
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A fixed mass of gas occupies 200 cm3 at a temperature of 230c and a pressure of 740 mm Hg.
Calculate the volume of the gas at -250c and 790 mm Hg pressure.
Date posted:
October 17, 2019
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A gas occupies 5dm3 at a temperature of -270C and 1 atmosphere pressure. Calculate the volume occupied by the gas at a pressure of 2 atmospheres and a temperature of 1270C
Date posted:
October 17, 2019
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The figure below shows two gases P and Q diffusing from two opposite ends 18 seconds after the experiment
(a) Which of the gases has a lighter density?
(b) Given that the molecular mass of gas Q is 17, calculate the molecular mass of P
Date posted:
October 17, 2019
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Gas B takes 110 seconds to diffuse through a porous pot, how long will it take for the same amount of ammonia to diffuse under the same conditions of temperature and pressure?
(RMM of B = 34 RMM of ammonia = 17)
Date posted:
October 17, 2019
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Below are structures of particles. Use it to answer questions that follow. In each case only electrons in the outermost energy level are shown
(a) Identify the particle which is an anion
(b) Choose a pair of isotopes. Give a reason
Date posted:
October 17, 2019
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A sample of Carbon (IV) Oxide takes 200 seconds to diffuse across a porous plug.
How long will it take the same amount of Carbon (II) Oxide to diffuse through the same plug?(C=12, O=16)
Date posted:
October 17, 2019