a)
(i) Liquid X - Dinitrogen tetra – oxide
(ii) Gas Y - Oxygen
b)Production of cracking noise when heated
marto answered the question on October 1, 2019 at 11:01
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The following diagram shows the effect of electric current on lead (II) Chloride
(Solved)
The following diagram shows the effect of electric current on lead (II) Chloride.
a) When the circuit was completed no current flowed. Explain why.
b) When lead (II) Chloride was heated to about 300 degrees C, it melted and there was light on the bulb. State and explain the observation made at the anode.
Date posted:
October 1, 2019
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Answers (1)
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Explain using chemical means how you would differentiate between carbon (II) oxide and carbon (IV) oxide.
(Solved)
Explain using chemical means how you would differentiate between carbon (II) oxide and carbon (IV) oxide.
Date posted:
October 1, 2019
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Answers (1)
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The diagram below shows the effect of sunlight on chlorine water
(Solved)
The diagram below shows the effect of sunlight on chlorine water.
a) Identify gas W
b) Write an equation to show the formation of gas W
c) Which compound is left in the beaker after complete formation of gas W?
Date posted:
October 1, 2019
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Answers (1)
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Form two students from Anestar Premier High School reacted three elements as shown in the table below
(Solved)
Form two students from Anestar Premier High School reacted three elements as shown in the table below.
Which element (s) is likely to be:
i) Non-metal (s)
ii) Metal (s)
iii) Insoluble in water
Date posted:
October 1, 2019
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Answers (1)
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If 25.0cm3 of 0.1 M H2SO4 solution neutralized a solution containing 1.06g of sodium carbonate in 250cm3 of solution, calculate the molarity and volume of...
(Solved)
If 25.0cm3 of 0.1 M H2SO4 solution neutralized a solution containing 1.06g of sodium carbonate in 250cm3 of solution, calculate the molarity and volume of the sodium carbonate solution used.
Date posted:
October 1, 2019
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Answers (1)
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What volume of oxygen will be required for complete combustion of 100cm3 of carbon (II) oxide. What is the volume of the product formed (All...
(Solved)
What volume of oxygen will be required for complete combustion of 100cm3 of carbon (II) oxide. What is the volume of the product formed (All volumes at same temperature and pressure
Date posted:
October 1, 2019
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Answers (1)
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A compound of carbon, hydrogen and oxygen contains 71.12g by mass of oxygen, 2.2g hydrogen and the rest is carbon. It has relative molecular mass...
(Solved)
A compound of carbon, hydrogen and oxygen contains 71.12g by mass of oxygen, 2.2g hydrogen and the rest is carbon. It has relative molecular mass of 90.
a) Determine the empirical formula of the compound
b) Determine the molecular formula of the compound
Date posted:
October 1, 2019
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Answers (1)
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The diagram below shows Chromatograms for five different dyes.
(Solved)
The diagram below shows Chromatograms for five different dyes.
a) Name one condition required to separate the chromatograms present in a dye.
b) What is meant by the solvent front? .
c) Which chromatograms are present in dye E.
d) Name two industrial applications of chromatography
Date posted:
October 1, 2019
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Answers (1)
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The set-up below was used to prepare a sample of oxygen gas. Study it and answer the questions that follow.
(Solved)
The set-up below was used to prepare a sample of oxygen gas. Study it and answer the questions that follow.
a) Write a word equation for the reaction that produces oxygen above.
b) State two physical properties of oxygen gas.
c) State two uses of oxygen.
Date posted:
October 1, 2019
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Answers (1)
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State whether solutions with the following pH values are acidic, basic or neutral.
pH 3 –
pH 11 –
pH 14 –
pH 7 –
(Solved)
State whether solutions with the following pH values are acidic, basic or neutral.
pH 3 –
pH 11 –
pH 14 –
pH 7 –
Date posted:
October 1, 2019
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Answers (1)
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Study the diagram below for the reaction between sodium carbonate and hydrochloric acid and answer the questions that follow
(Solved)
Study the diagram below for the reaction between sodium carbonate and hydrochloric acid and answer the questions that follow.
a) Explain what was observed in:
i) Test tube A.
ii) Test tube B.
b) Write a word equation for the reaction which took place in test tube.
Date posted:
October 1, 2019
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Answers (1)
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Distinguish between temporary physical and permanent chemical changes.
(Solved)
Distinguish between temporary physical and permanent chemical changes.
Date posted:
October 1, 2019
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Answers (1)
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The graph below shows the shape of the curve obtained by a student when solid X was heated to boiling.
(Solved)
The graph below shows the shape of the curve obtained by a student when solid X was heated to boiling.
a) Determine the melting point of solid X.
b) After the experiment the student concluded that substance x was pure substance. Explain why he concluded so.
c) If candle wax was used in the above experiment the portion QR would be horizontal. What does this tell us about candle wax?
Date posted:
October 1, 2019
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Answers (1)
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Identify the elements present in the following compounds.
i) Magnesium oxide.
ii) Zinc chloride
iii) Sodium sulphate.
iv) Aluminium nitrate
(Solved)
Identify the elements present in the following compounds.
i) Magnesium oxide.
ii) Zinc chloride
iii) Sodium sulphate.
iv) Aluminium nitrate
Date posted:
October 1, 2019
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Answers (1)
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Explain why molten calcium chloride conducts electricity while silicon (IV) oxide does not.
(Solved)
Explain why molten calcium chloride conducts electricity while silicon (IV) oxide does not.
Date posted:
October 1, 2019
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Answers (1)
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Phosphorus element smoulders in air to form two oxides
(a) Name the two oxides
(b) State the nature of the solution when the above mentioned oxides are...
(Solved)
Phosphorus element smoulders in air to form two oxides
(a) Name the two oxides
(b) State the nature of the solution when the above mentioned oxides are dissolved in water.
Date posted:
October 1, 2019
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Answers (1)
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The diagrams below are some common laboratory apparatus. Name each apparatus and state its use.
(Solved)
The diagrams below are some common laboratory apparatus. Name each apparatus and state its use.
Date posted:
October 1, 2019
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Answers (1)
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(a) What name is given to the two types of atoms.
(Solved)
(a) What name is given to the two types of atoms.
Date posted:
October 1, 2019
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Answers (1)
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Oxygen is obtained on large scale by the fractional distillation of air as shown on the flow chart below.
(Solved)
Oxygen is obtained on large scale by the fractional distillation of air as shown on the flow chart below.
a) Explain why air is considered as a mixture
b) Identify the substance that is removed at the filtration stage
c) Explain why Carbon (IV) oxide and water are removed before liquefaction of air
d) Identify the component that is collected at -186°C
Date posted:
October 1, 2019
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Answers (1)
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In temperate countries, salt is sprayed on roads to defrost and clear roads but the long term effect on this practice is costly to motorist.
(a)...
(Solved)
In temperate countries, salt is sprayed on roads to defrost and clear roads but the long term effect on this practice is costly to motorist.
(a) Explain the role of salt in defrosting the ice.
(b) Explain why the long term effect is costing to motorist.
Date posted:
October 1, 2019
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Answers (1)