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- Cheptoo set-up some apparatus as shown in the diagram below:-(Solved)
Cheptoo set-up some apparatus as shown in the diagram below:-
At the start of the experiment, the bulb did not light:-
(a) State and explain the observation made when the tap was opened to allow the hydrogen chloride gas through the water for about 20 minutes
(b) Write the chemical equation for the reaction that took place at the cathode
Date posted: October 31, 2019. Answers (1)
- A student performed the following experiment with an intention to extract calcium metal(Solved)
A student performed the following experiment with an intention to extract calcium metal
(i) The student was surprised that no calcium was produced in the experiment. Explain why no calcium was produced
(ii) Write the equation for the reaction that occurred at the anode if the solution was concentrated
(iii) The electrolysis involved passing an electric current of 4A for one hour. Calculate the mass of
the product at the anode. (1Faraday = 96500C, Cl =35.5, H = 1.0, O =16, Ca = 40)
Date posted: October 31, 2019. Answers (1)
- A strip of copper metal was immersed into a nitrate solution of metal Q overnight. Use the information below to answer questions that follow(Solved)
A strip of copper metal was immersed into a nitrate solution of metal Q overnight. Use the information below to answer questions that follow
(a) State the observations made at the end of the experiment
(b) Give a reason for the observations made in (a) above
(c) Calculate the e.m.f of the cell above
Date posted: October 31, 2019. Answers (1)
- Below are the standard electrode potentials for electrodes B and D(Solved)
Below are the standard electrode potentials for electrodes B and D
(i) Identify the electrode which is ;
(a) The least reducing agent
(b) The strongest oxidizing agent
(ii) Calculate the e.m.f of the cell formed when the two electrodes are connected
(iii) Write a cell representative for the cell above
Date posted: October 31, 2019. Answers (1)
- The flow chart below shows an analysis of mixture R that contains two salts. Study it and answer the questions that follow:-(Solved)
The flow chart below shows an analysis of mixture R that contains two salts. Study it and answer the questions that follow:-
(i) Write two ionic equations for the reactions between the cation in filtrate X and aqueous
ammonia (Ammonium hydroxide)until in excess
(ii) What conclusion can be drawn from Step IV only? Explain
(iii) What observation would indicate the presence of a NO3- ion in step I?
(iv) Write the formula of the anion in residue V. Explain
(v) Suggest the identity of the cation present in solution Z
(vi) Name the two salts present in mixture R
Date posted: October 29, 2019. Answers (1)
- Study carefully the information given below and answer the questions that follow:-(Solved)
Study carefully the information given below and answer the questions that follow:-
(a) Identify the substances represented by the letters
(b) Give equations for the reactions in which:-
(i) Substance B is formed from the solution of A on electrolysis
(ii) Substance B is formed from solution A when reacted with E
(c) Give one use of gas C
(d) Name the ion responsible for the deep blue solution
Date posted: October 29, 2019. Answers (1)
- When nitrate solution of a certain metal X was electrolysed, 1.174g of metal X was deposited by a current of 4 amperes flowing for 16...(Solved)
When nitrate solution of a certain metal X was electrolysed, 1.174g of metal X was deposited by a current of 4 amperes flowing for 16 minutes. Determine the formula of the metal nitrate. (1F= 96,500, R.A.M of X= 59)
Date posted: October 29, 2019. Answers (1)
- Calculate the electromotive force of a cell where the overall reaction is:-(Solved)
Calculate the electromotive force of a cell where the overall reaction is:-
Date posted: October 29, 2019. Answers (1)
- The standard electrode potential for the elements chlorine and magnesium are:-(Solved)
The standard electrode potential for the elements chlorine and magnesium are:-
Which one of the two elements will act as an oxidizing agent? Explain.
Date posted: October 29, 2019. Answers (1)
- The table gives the standard redox potentials for a number of half reactions. Use it to answer the questions that follow:-(Solved)
The table gives the standard redox potentials for a number of half reactions. Use it to answer the questions that follow:-
(i) Relative to which half-cell reaction are the above electrode potentials expressed?
(ii) Calculate the e.m.f of the cell made up by combining the 
electrode and 
electrode
(iii) Which of the substances listed in the above table is :-
I. The strongest oxidising agent
II. The strongest reducing agent
(iv) Which substances could be used to convert iodide ions to iodine? Write balanced equations for any possible conversions
Date posted: October 29, 2019. Answers (1)
- When a current of 6.42 A was passed through an electrolyte Y2+ ions for 10 minutes,2.74 of Y were deposited
(i) Calculate the quantity of electricity...(Solved)
When a current of 6.42 A was passed through an electrolyte Y2+ ions for 10 minutes,2.74 of Y were deposited
(i) Calculate the quantity of electricity passed in the experiment
(ii) Determine the relative atomic mass of Y (1 Faraday = 96000 coulombs)
Date posted: October 29, 2019. Answers (1)
- Study the standard electrode potential for the half-cells given below and answer the questions that follow.(The letter do not represent the actual symbols of the...(Solved)
Study the standard electrode potential for the half-cells given below and answer the questions that follow.(The letter do not represent the actual symbols of the elements)
i) Identify the strongest oxidizing agents. Give a reason for your answer
ii) Which two half-cells would produce the highest potential difference when combined?
iii) In the space below draw a complete electro-chemical cell of the two-half cells mentioned
in (ii) above
Date posted: October 29, 2019. Answers (1)
- Consider the cell diagram below(Solved)
Consider the cell diagram below:
i) Write the overall cell reaction for the above electrochemical cell
ii) Given that 
value for 
is -0.40V,calculate the value for 
Date posted: October 29, 2019. Answers (1)
- The reaction blow is a redox reaction(Solved)
The reaction blow is a redox reaction
(a) Identify the species reduced. Explain
(b) Write the equation for the oxidation reaction
Date posted: October 29, 2019. Answers (1)
- Sodium metal reacts with oxygen according to the following equation:-(Solved)
Sodium metal reacts with oxygen according to the following equation:-
State one physical and one chemical difference between Na2O2 and Na2O
Physical difference......
Chemical difference......
Date posted: October 29, 2019. Answers (1)
- Study the electrode potentials in the table below and answer the question that follow:
(Letters are not the actual symbols of elements)(Solved)
Study the electrode potentials in the table below and answer the question that follow:
(Letters are not the actual symbols of elements)
(a) Which one is the strongest reducing agent?
(b) Write the ionic equation for the reaction that takes place when Z is dipped in a solution
of G+ ions
(c) Calculate the 
cell value of the reaction in (b) above
Date posted: October 29, 2019. Answers (1)
- 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 gas Q
(b) With the help of diagram, describe how step (V) is carried out
Date posted: October 29, 2019. Answers (1)
- What mass of Zinc will be deposited from a solution of Zinc (II) Chloride when a current of 3A is passed through the Zinc (II)...(Solved)
What mass of Zinc will be deposited from a solution of Zinc (II) Chloride when a current of 3A is passed through the Zinc (II) Chloride solution during electrolysis for 50 minutes?
(Zn= 65, 1 Faraday = 96500C)
Date posted: October 29, 2019. Answers (1)
- In an electrolysis, a current of 200A was passed through molten oxide of metal Q for 58 minutes and 64.8g of the metal deposited. Determine;
i)...(Solved)
In an electrolysis, a current of 200A was passed through molten oxide of metal Q for 58 minutes and 64.8g of the metal deposited. Determine;
i) Charge on metal Q
ii) The volume of oxygen gas produced at standard temperature and pressure
Q = 27 IF = 96500C, molar gas volume stp =22.4dm3
Date posted: October 29, 2019. Answers (1)
- Two experiments were carried out as follows and the volume of hydrogen gas evolved measured at intervals of 10 seconds for 100 seconds.
(i) 8cm of...(Solved)
Two experiments were carried out as follows and the volume of hydrogen gas evolved measured at intervals of 10 seconds for 100 seconds.
(i) 8cm of magnesium ribbon was added to 1M hydrochloric acid
(ii) 8cm of magnesium ribbon was added to 0.5M hydrochloric acid
Graphs of volume of hydrogen evolved against time were plotted
(i) Which of the graph was obtained for reaction above? Explain
(ii) Explain the general shape of the graph
Date posted: October 29, 2019. Answers (1)