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- Study the equation below:(Solved)
Study the equation below:
Mg(s) + 2H2O(l)------->Mg(OH)2(aq) + H2(g)
Which species has undergone oxidation .Explain
Date posted: October 15, 2019. Answers (1)
- Work out the oxidation number of phosphorous in the following compound H3PO3(Solved)
Work out the oxidation number of phosphorous in the following compound H3PO3
Date posted: October 15, 2019. Answers (1)
- Study the table below and answer the questions that follow.(Solved)
Study the table below and answer the questions that follow.
(i) Complete the table above
(ii) From the table, choose the most reactive metal. Explain
(iii) Which element is the most electronegative. Explain
(iv) Using dots (.) and crosses (x) to represent electrons, show the bonding in the chloride of Q
(v) Explain the solubility of element T in water
(b) (i) Why is aluminium used to make utensils yet it is a reactive metal?
Date posted: October 15, 2019. Answers (1)
- The grid below shows a part of the periodic table. The letters do not represent the actual symbols.(Solved)
The grid below shows a part of the periodic table. The letters do not represent the actual symbols.
Use it to answer the questions that follow:-
(a) How do the atomic radius of element X and Y compare
(b) (i) Using crosses (X) to represent electrons, draw the atomic structure of element Q
(ii) State the period and the group to which element Q belong
(c) (i) The ionic configuration of element G is 2.8 G forms an ion of the type G-1.
Indicate on the grid, the position of element G.
(ii) To which chemical family does element G belong?
(iii) State one use of element U
(iv) What is the nature of the compound formed between K and U
Date posted: October 15, 2019. Answers (1)
- The following flow chart shows the industrial manufacture of Nitric (V) acid.(Solved)
The following flow chart shows the industrial manufacture of Nitric (V) acid.
a) Identify substance B, C, E and F.
b) Describe what happens in the catalytic chamber.
c) State what takes place in chamber D.
d) 60 – 65% nitric (V) acid is produced in the absorption chamber. Describe how the acid can be
concentrated.
Date posted: October 14, 2019. Answers (1)
- The grid below is part of the periodic table. Use it to answer the questions that follow:(Solved)
The grid below is part of the periodic table. Use it to answer the questions that follow:
a) Write down the formula of the compound formed between C and A.
b) Which element has the same electron arrangement as the stable ion of:
(i) F (ii) A
c) Element Q has atomic number 15. Indicate its position on the grid.
d) Explain how the atomic radii of the following compare:
(i) C and F
(ii) C and D
e) Write the type of bond present in a compound formed between D and A.
f) Compound C and G were completely burned in oxygen.
(i) Write down equations to show the combustion of each of the elements.
(ii) State whether each of the oxides (i) above is basic or acidic.
Date posted: October 14, 2019. Answers (1)
- Define the term melting point of a substance(Solved)
Define the term melting point of a substance
Date posted: October 14, 2019. Answers (1)
- An ion of oxygen is larger than oxygen atom. Explain(Solved)
An ion of oxygen is larger than oxygen atom. Explain
Date posted: October 14, 2019. Answers (1)
- The table below gives information about the ions T+ and Z2-(Solved)
The table below gives information about the ions T+ and Z2-
(a) How many protons are there in the nucleus of ?
(i) Element T?
(ii) Element Z?
(b) Determine the relative formula mass of the compound formed between T and Z
(c) State two conditions under which the compound would conduct electricity
Date posted: October 14, 2019. Answers (1)
- An oxide of element G has the formula as G2O3
(a) State the valency of element G
(b) In which group of the periodic table is element...(Solved)
An oxide of element G has the formula as G2O3
(a) State the valency of element G
(b) In which group of the periodic table is element G?
Date posted: October 14, 2019. Answers (1)
- An element M has two isotopes M and M . The relative atomic mass of the naturally occurring is 63.55. Calculate the percentage of each...(Solved)
An element M has two isotopes M and M . The relative atomic mass of the naturally occurring is 63.55. Calculate the percentage of each isotope
Date posted: October 14, 2019. Answers (1)
- The following refers to element Y(Solved)
The following refers to element Y
Given that isotope C contains 31 neutrons in its nucleus,find the number of protons in isotope B
Date posted: October 14, 2019. Answers (1)
- Element V has two isotopes. Two thirds of V and one third of V . What is the relative atomic mass of element V?(Solved)
Element V has two isotopes. Two thirds of V and one third of V . What is the relative atomic mass of element V?
Date posted: October 14, 2019. Answers (1)
- Element A has atomic mass 23 and element B has atomic mass 7 and also have 12 neutrons and 4 neutrons respectively.
(a) Write the electronic...(Solved)
Element A has atomic mass 23 and element B has atomic mass 7 and also have 12 neutrons and 4 neutrons respectively.
(a) Write the electronic arrangement of A and B
(b) Which element has higher ionization energy? Explain
Date posted: October 14, 2019. Answers (1)
- In an experiment an unknown mass of anhydrous sodium carbonate was dissolved in water and the solution made up to 250cm3. 25cm3 of this solution...(Solved)
In an experiment an unknown mass of anhydrous sodium carbonate was dissolved in water and the solution made up to 250cm3. 25cm3 of this solution neutralized 20cm3 of 0.25M nitric acid.
(Na = 23.0 C = 12.0 O = 16.0)
Calculate:
(a) Moles of Nitric acid used
(b) Moles of sodium carbonate in 25cm of the solution
(c) Mass of unknown sodium carbonate used
Date posted: October 14, 2019. Answers (1)
- Between N and M which part should be heated first? Explain(Solved)
(a) Between N and M which part should be heated first? Explain
(b) Write a chemical equation for the reaction occurring in the combustion tube.
Date posted: October 14, 2019. Answers (1)
- Jane set-up the experiment as shown below to collect a gas. The wet sand was heated before heating Zinc granules.(Solved)
Jane set-up the experiment as shown below to collect a gas. The wet sand was heated before heating Zinc granules.
(a) Complete the diagram for the laboratory preparation of the gas
(b) Why was it necessary to heat wet sand before heating Zinc granules?
Date posted: October 14, 2019. Answers (1)
- When hydrogen is burnt and the product cooled, the following results are obtained as shown in the diagram below:(Solved)
When hydrogen is burnt and the product cooled, the following results are obtained as shown in the diagram below:
(a) Write the equation for the formation of liquid Y
(b) Give a chemical test for liquid Y
Date posted: October 14, 2019. Answers (1)
- Gas P was passed over heated magnesium ribbon and hydrogen gas was collected as shown in the diagram below:(Solved)
Gas P was passed over heated magnesium ribbon and hydrogen gas was collected as shown in the diagram below:
(i) Name gas P
(ii) Write an equation of the reaction that takes place in the combustion tube
(iii) State one precaution necessary at the end of this experiment
Date posted: October 14, 2019. Answers (1)
- The setup below was used to investigate the reaction between metals and water.(Solved)
The setup below was used to investigate the reaction between metals and water.
(a) Identify solid X and state its purpose
Solid X
Purpose
(b) Write a chemical equation for the reaction that produces the flame.
Date posted: October 14, 2019. Answers (1)