-
Why is the boiling point of propanol higher than that of pentane?
Date posted:
August 13, 2018
-
Rates and reactions:
A form 4 student carried out an experiment with 40 cubic centimeters of 1.0M hydrochloric acid and Marble chips in order to determine rates of reaction using the following steps.
??HCL was poured to a conical flask
??Conical flask was then placed on a weighing balance
??20 grams of marble chips was then added to acid and left for reaction to proceed
??With time, Changes in mass of flask with contents was recorded
(a) State other way in which one can measure rate of reacion(1mk)
(b)(i) Sketch curve that will be obtain if mass of contents in flask is plotted against time label it as (k) (2mks)
(ii) Using the same axes sketch curve that will be obtain if powdered marble had been used(1mk)
(c) Write a chemical equation to show how reaction proceed (1mk)
Date posted:
August 13, 2018
-
Explain how a mixture of sulphur and sodium chloride can be separated into solid sulphur and sodium chloride
Date posted:
August 2, 2018
-
Solution of hydrogen chloride gas in water produces hydrogen gas with zinc granules, but solution of hydrogen chloride in toluene doesn't. Explain. (2 marks)
Date posted:
July 25, 2018
-
Give one chemical test to distinguish between ethane and ethene.
Date posted:
July 7, 2018
-
Why do cars in Mombasa rust faster than those in Kisumu?
Date posted:
July 7, 2018
-
The density of brass is 8.3g/cm3 and that of tin is 7.3g/cm3. What volume of tin would have the same mass as 73g of brass?
Date posted:
July 5, 2018
-
A student was stung by a bee and sodium hydrogen carbonate was applied to relieve the pain. Explain.
Date posted:
July 4, 2018
-
100g of a radio active substance was reduced to 12.5 g in 15.6 years. Calculate the half-life of the substance.
Date posted:
July 4, 2018
-
Copper (II) oxide and charcoal are both black solids. Describe how you can distinguish them.
Date posted:
July 1, 2018
-
Explain the following observations when burning magnesium is lowered into a gas jar of carbon(4) oxide it continues burning,but when burning zinc is lowered into a gas jar of carbon (4) oxide it does not burn.
Date posted:
June 24, 2018
-
Which alkanol is mixed with a cleansing agent during its preparation?
Date posted:
June 24, 2018
-
What is the difference between fractional distillation and fractional crystallization?
Date posted:
June 23, 2018
-
What is the difference of alkali and alkaline?
Date posted:
June 22, 2018
-
Factors influencing size of ionisation energy of an element
Date posted:
June 21, 2018
-
What is lampblack?
Date posted:
June 20, 2018
-
What mass of sodium hydroxide would be neededto neutralize exactly 200 cubic centimetre of a solution containing 49 grammes of sulphuric acid in dm^-3
Date posted:
June 18, 2018
-
Describe Werner's coordination theory and give his main proposals.
Date posted:
May 22, 2018
-
Explain Pearson's rule and Jorgen's rule as used in coordination chemistry.
Date posted:
May 20, 2018
-
Organometallics
Date posted:
May 20, 2018
-
Differentiate between the terms isomers and polymers.
Date posted:
May 20, 2018
-
State the assumptions of capture recapture method of population size estimation.
Date posted:
May 19, 2018
-
Explain why sodium hydroxide is preferred when making a setup to investigate the active part of air using a burning candle.
Date posted:
May 14, 2018
-
The Haber process largely relies on catalysts. Give reason for this.
Date posted:
May 12, 2018
-
Name the industrial process by which ammonia gas is produced.
Date posted:
May 10, 2018
-
Name the three oxides of nitrogen.
Date posted:
May 10, 2018
-
State the properties of nitrogen(I)oxide gas
Date posted:
May 10, 2018
-
Describe the process of obtaining nitrogen gas from air by fractional distillation of liquid air.
Date posted:
May 10, 2018
-
Using chemical equations, describe the process of producing nitric acid.
Date posted:
May 5, 2018
-
What is Ostwald process?
Date posted:
May 5, 2018