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- Sodium hydroxide can be prepared through the following methods: I and II.(Solved)
Sodium hydroxide can be prepared through the following methods: I and II.
a) Name one precaution that needs to be taken in method I.
b) Give the name of process A.
c) Describe the chemical test of hydrogen gas.
Date posted: September 18, 2019.
- If p = , express q in terms of p (Solved)
If p =
, express q in terms of p
Date posted: September 18, 2019.
- Describe how a student can determine the purity of tap water in a school laboratory.(Solved)
Describe how a student can determine the purity of tap water in a school laboratory
Date posted: September 18, 2019.
- Use logarithms to four decimal places to evaluate. (Solved)
Use logarithms to four decimal places to evaluate.
![fig151892019911.png](/questions/uploads/fig151892019911.png)
Date posted: September 18, 2019.
- Study the flow chart below and answer the questions that follow.(Solved)
Study the flow chart below and answer the questions that follow.
(a) Name the substance
(i) A
(ii) B
(b) State the property of S02 exhibited in step 2.
Date posted: September 18, 2019.
- Ethanol has a molar heat of combustion of -1360kJmol-1. Calculate the heating value of ethanol. (C=12,H=1,O=16(Solved)
Ethanol has a molar heat of combustion of -1360kJmol-1. Calculate the heating value of ethanol. (C=12,H=1,O=16
Date posted: September 18, 2019.
- In an experiment two equal volumes of solution L and M were placed into visking tubing. The visking tubing was suspended into beakers containing equal...(Solved)
In an experiment two equal volumes of solution L and M were placed into visking tubing. The visking tubing was suspended into beakers containing equal volumes of solutions K. The set –up is as shown in the diagram A and B. The set-up was allowed to stand for 45 minutes and results are as shown in the diagrams.
(a) Name the process that was being demonstrated.
(b) Explain the results that were obtained at the end of the experiment in
(i) Set-up A.
(ii) Set up B.
Date posted: September 18, 2019.
- A volume of 10cm3 of ethene gas (C2H4) was exploded with 50cm3 of oxygen.
(i) Write the equation of the reaction for the combustion of ethene.
(ii)...(Solved)
A volume of 10cm3 of ethene gas (C2H4) was exploded with 50cm3 of oxygen.
(i) Write the equation of the reaction for the combustion of ethene.
(ii) Calculate the volume of gaseous mixture.
Date posted: September 18, 2019.
- A bag A has 5 green marbles, 9 red marbles and Y blue marbles, all identical except for colour. The total number of marbles in...(Solved)
A bag A has 5 green marbles, 9 red marbles and Y blue marbles, all identical except for colour. The total number of marbles in the bag is two more than double the number of blue marbles.
Three marbles are then randomly picked one at a time from bag A and placed in bag B.
(a) Find the value of Y.
(b) Find the probability that;
(i) The first two marbles picked are green
(ii) All the three marbles are of different colour
(iii) At least one of the three marbles placed in bag B are blue.
(iv) At most two marbles are red.
Date posted: September 18, 2019.
- Both molten sodium chloride and molten sodium metal conducts electricity. Explain how each of these conducts electricity
(i) Molten sodium chloride
(ii) Molten sodium metal(Solved)
Both molten sodium chloride and molten sodium metal conducts electricity. Explain how each of these conducts electricity
(i) Molten sodium chloride
(ii) Molten sodium metal
Date posted: September 18, 2019.
- During the electrolysis, a current of 2 amperes was passed through the copper (II) sulphate solution for 4 hours. Calculate the volume of the gas...(Solved)
During the electrolysis, a current of 2 amperes was passed through the copper (II) sulphate solution for 4 hours. Calculate the volume of the gas produced at the anode. (1 F= 96500 C, MGV = 24000cm3).
Date posted: September 18, 2019.
- Below is a sketch of the area bounded by the curve y=x2+3 and the line x=-2, x=4 and y=0.
(a) Estimate the area of the shaded...(Solved)
Below is a sketch of the area bounded by the curve y=x2+3 and the line x=-2, x=4 and y=0.
(a) Estimate the area of the shaded region using 6 strips by:
(i) The trapezoidal rule
(ii) Integration
(b) Find the percentage error in the area for the approximation in (a)(i) if the value in (a)(ii) is taken
as the exact area.
Date posted: September 18, 2019.
- The solubility of iron (II) sulphate at 22oC is 15.65g/100g of water. Calculate the mass of iron (II) sulphate crystals in 90g of saturated iron...(Solved)
The solubility of iron (II) sulphate at 22oC is 15.65g/100g of water. Calculate the mass of iron (II) sulphate crystals in 90g of saturated iron (II) sulphate solution.
Date posted: September 18, 2019.
- Use the following information to answer the questions that follow.(Solved)
Use the following information to answer the questions that follow.
a) Draw an energy cycle diagram and label the various heat changes.
b) Use the energy circle above to calculate heat of formation of methanol.
Date posted: September 18, 2019.
- A farmer has two tractors, A and B. The tractors working together can plough a farm in 2½ hours. One day the tractors started to...(Solved)
A farmer has two tractors, A and B. The tractors working together can plough a farm in 2½ hours. One day the tractors started to plough the farm together. After one hour ten minutes, tractor B broke down but A continued alone and completed the job after a further four hours.
(a) The fraction of the job done by tractor A after tractor B broke down.
(b) The time each tractor working alone would have taken to plough the farm.
Date posted: September 18, 2019.
- A point P divides line AB in the ratio 7:-5 where A and B are the points A(2,5,4) and B(-4,7,2). Find the co-ordinates of P....(Solved)
A point P divides line AB in the ratio 7:-5 where A and B are the points A(2,5,4) and B(-4,7,2). Find the co-ordinates of P.
Date posted: September 18, 2019.
- Differentiate between a monomer and polymer.(Solved)
Differentiate between a monomer and polymer.
Date posted: September 18, 2019.
- A two-digit positive number is such that the sum of its digits is nine. When the digits are reversed, the new number formed exceeds...(Solved)
A two-digit positive number is such that the sum of its digits is nine. When the digits are reversed,the new number formed exceeds the original number by 27. Find the original number.
Date posted: September 18, 2019.
- The equation of a circle, centre (-3,5) and radius 4 units is given as x2+y2+ax+by+c=0. Find the constants a, b and c.(Solved)
The equation of a circle, centre (-3,5) and radius 4 units is given as x2+y2+ax+by+c=0. Find the constants a, b and c.
Date posted: September 18, 2019.
- Pentanoic acid reacts with butan – 1 – 0l to form an organic compound.(Solved)
Pentanoic acid reacts with butan – 1 – 0l to form an organic compound.
(i) Write an equation to show the above reaction.
(ii) What is the name given to the above type of reaction?
(iii) A few drops of a certain catalyst must be added to the mixture to increase the rate of the reaction.
(a) Name the catalyst.
(b) Explain the role of the catalyst in the above reaction.
Date posted: September 18, 2019.
- An approximation of fraction below is obtained by rounding off each value in the numerator to 4 significant figures and truncating each value in the...(Solved)
An approximation of fraction below is obtained by rounding off each value in the numerator to 4 significant figures and truncating each value in the denominator to 2 significant figures.
Find the approximate value of the resulting quotient, correct to 1 decimal place.
Date posted: September 18, 2019.
- Two methods of preparing alkenes are shown by the following general equations.(Solved)
Two methods of preparing alkenes are shown by the following general equations.
(a) What type of reactions are described by equations;
(i)and (ii)
(b) Which of the two methods is used on a large scale.
Date posted: September 18, 2019.
- (a) Expand (1+3x)5 in ascending powers of x up to the term in x3 and simplify.
(b) Hence estimate the value of (0.97)5 correct to...(Solved)
(a) Expand (1+3x)5 in ascending powers of x up to the term in x3 and simplify.
(b) Hence estimate the value of (0.97)5 correct to 4 decimal places.
Date posted: September 18, 2019.
- A box open at the top with a square base is made of 300cm2 of thin sheet metal. If x cm is the length of...(Solved)
A box open at the top with a square base is made of 300cm2 of thin sheet metal. If x cm is the length of the base and Vcm3 is the maximum possible volume of the box, calculate the value of V.
Date posted: September 18, 2019.
- Draw the structural formula of the following compounds:-
(i) 2 – melthylhex –l-ene
(ii) Butan –l-ol(Solved)
Draw the structural formula of the following compounds:-
(i) 2 – melthylhex –l-ene
(ii) Butan –l-ol
Date posted: September 18, 2019.
- Find the sum of all terms in the Arithmetic Progression (A.P) below:
53 + 46 + 39 +……….+ -10
(Solved)
Find the sum of all terms in the Arithmetic Progression (A.P) below:
53 + 46 + 39 +……….+ -10
Date posted: September 18, 2019.
- Name two regions in human body that displays counter-current flow system.(Solved)
Name two regions in human body that displays counter-current flow system.
Date posted: September 17, 2019.
- State the type of placentation found in the following fruits.
i) Pawpaw
ii) Orange
iii) Bean pod(Solved)
State the type of placentation found in the following fruits.
i) Pawpaw
ii) Orange
iii) Bean pod
Date posted: September 17, 2019.
- Study the diagram below and answer question that follow.(Solved)
Study the diagram below and answer question that follow.
i) Epithelial layer above is located in the nasal cavity.
Name the structure labeled A and B
ii) State the significance of the structure A.
Date posted: September 17, 2019.
- Diagram below represents a type of muscle.(Solved)
Diagram below represents a type of muscle.
a) Identify the type of muscle shown above.
b) Name two parts of human body where this type of muscle can be found.
Date posted: September 17, 2019.