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(i) 100 – 1100C
(ii) Impure - it melts and boils over a range of temperature.
(iii) - Increases the boiling point.
maurice.mutuku answered the question on September 12, 2019 at 05:12
- The curves below represent the volume of carbon (IV) oxide gas evolved when 1M concentrated hydrochloric acid and 60g of calcium carbonate and also 0.5M...(Solved)
The curves below represent the volume of carbon (IV) oxide gas evolved when 1M concentrated hydrochloric acid and 60g of calcium carbonate and also 0.5M concentrated hydrochloric acid was reacted with the same quantity of the carbonate.
(a) Which of the curves represent the reaction of 1M concentrated hydrochloric acid with powdered calcium carbonate.
Explain.
(b) Explain why the curves flatters at the same level of production of carbon (IV) oxide.
Date posted: September 12, 2019. Answers (1)
- Study the diagram and use it to answer the question that follow.(Solved)
Study the diagram and use it to answer the question that follow.
(i) State the observations in the combustion tube.
(ii) Describe the chemical test for product B.
Date posted: September 11, 2019. Answers (1)
- Complete the table below.(Solved)
Complete the table below.
Date posted: September 11, 2019. Answers (1)
- Nitrogen (II) oxide can be prepared by catalytic oxidation of ammonia. Name the catalyst used in the process.(Solved)
Nitrogen (II) oxide can be prepared by catalytic oxidation of ammonia. Name the catalyst used in the process.
Date posted: September 11, 2019. Answers (1)
- When hydrocarbon was completely burnt in air, 2.51g of carbon (IV) oxide and 1.28g of water were formed. Given that the compound has a relative...(Solved)
When hydrocarbon was completely burnt in air, 2.51g of carbon (IV) oxide and 1.28g of water were formed. Given that the compound has a relative molecular mass of 58, find its molecular formular (C = 12, H=1).
Date posted: September 11, 2019. Answers (1)
- During electrolysis of a sulphate of metal M, using M electrodes, a current of 0.5A was passed through the solution for 12 minutes, 52 seconds....(Solved)
During electrolysis of a sulphate of metal M, using M electrodes, a current of 0.5A was passed through the solution for 12 minutes, 52 seconds. The mass at the cathode increases from 2.40g to 2.44g. Determine the charge of metal M (1f = 96500C,M = 20).
Date posted: September 11, 2019. Answers (1)
- Ammonia gas can be prepared as shown:(Solved)
Ammonia gas can be prepared as shown:
State and explain the observations made if the pressure is increased in the system.
Date posted: September 11, 2019. Answers (1)
- Study the table below and answer the questions that follow.(Solved)
Study the table below and answer the questions that follow.
(a) Write the formula of the chloride of element K.
(b) With reason(s) compare the melting point of the chlorides of element K to that of element L
Date posted: September 11, 2019. Answers (1)
- Xg of sodium hydroxide were dissolved in distilled water to make 100cm3 of solution 40cm3 of this solution required 25cm3 of 1M sulphuric (VI) acid....(Solved)
Xg of sodium hydroxide were dissolved in distilled water to make 100cm3 of solution 40cm3 of this solution required 25cm3 of 1M sulphuric (VI) acid. Determine the mass of X of solution of sodium hydroxide (Na = 23, O = 16, H = 1)
Date posted: September 11, 2019. Answers (1)
- A section of a polymer has the following structure.(Solved)
A section of a polymer has the following structure.
A sample of this polymer is found to have a molecular mass of 1500.
Determine the number of monomers in the polymer (H = 1, C = 12, Cl = 35.5)
Date posted: September 11, 2019. Answers (1)
- Calculate the enthalpy of formation of propane.(Solved)
Given that:
Calculate the enthalpy of formation of propane.
Date posted: September 11, 2019. Answers (1)
- The following set-up was used to prepare Carbon (II) Oxide in laboratory.(Solved)
The following set-up was used to prepare Carbon (II) Oxide in laboratory.
(a) Name liquid X and state its value.
(b) Explain why the gas is collected over water.
Date posted: September 11, 2019. Answers (1)
- Give the name of the following organic compound.(Solved)
Give the name of the following organic compound.
(a) 
(b) 1 mole of HBr reacts with propene molecules. Draw the structure and name the compound formed.
Date posted: September 11, 2019. Answers (1)
- When 75cm3 of a gaseous hydro-carbon CxHy burns in 250cm3 of oxygen,25cm3 of oxygen is unused, 150cm3 of carbon (IV) oxide is formed. Determine the...(Solved)
When 75cm3 of a gaseous hydro-carbon CxHy burns in 250cm3 of oxygen,25cm3 of oxygen is unused, 150cm3 of carbon (IV) oxide is formed. Determine the volume of steam formed hence deduce the formular of the Hydro-carbon.
Date posted: September 11, 2019. Answers (1)
- Using relevant equations show that zinc oxide is an amphoteric oxide.(Solved)
Using relevant equations show that zinc oxide is an amphoteric oxide.
Date posted: September 11, 2019. Answers (1)
- An isotope M has 20 neutrons and a mass number of 37.(Solved)
An isotope M has 20 neutrons and a mass number of 37.
(i) Draw the atomic structure of M.
(ii) To which group does M belong? Explain.
Date posted: September 11, 2019. Answers (1)
- The diagram below represents a flame of the Bunsen burner.(Solved)
The diagram below represents a flame of the Bunsen burner.
A piece of paper is flipped over the flame as shown in the diagram. Draw a sketch to show the outcome.
Date posted: September 11, 2019. Answers (1)
- The chart below represents the extraction of iron and some of its uses.(Solved)
The chart below represents the extraction of iron and some of its uses.
(a) Name the raw materials fed into the blast furnace.
(b) Name 3 exhaust gases emitted from the blast furnace.
(c) (i) Why is it necessary to convert pig iron into wrought iron
(ii) State one commercial use of iron.
(d) Name substances A,B,C,X,Y
(e) i) Write equations for reactions in steps II and II
ii) Write an ionic equation for the reaction in step I.
iii) What observations are made in steps I and II?
Date posted: September 11, 2019. Answers (1)
- Experiment was set as shown below.(Solved)
Experiment was set as shown below.
(a) What is observed on the bulb when the switch is closed?
(b) Which electrode will be cathode?
(c) Write down the half-cell equations for:
(i) Copper electrode.
(ii) Zinc electrode.
(d) Write the overall ionic equation for the electrochemical cell.
(e) The table below shows the electrode potentials.
What is the value of the voltage of the cell?
(f) The switch is kept closed. State and explain the observation expected after sometime on the
(i) The zinc rod.
(ii) Copper (II) Sulphate solution.
Date posted: September 11, 2019. Answers (1)
- The enthalpies of combustion of carbon, hydrogen and ethanol are given below.(Solved)
The enthalpies of combustion of carbon, hydrogen and ethanol are given below.
i) Draw an energy cycle diagram that links the enthalpy of formation of ethanol to enthalpies of combustion of Carbon,hydrogen and ethanol.
ii) Determine the enthalpy of formation of ethanol
Date posted: September 11, 2019. Answers (1)