i) Zinc is more reactive// higher reduction potential than copper it will react with//get oxidized in preference to iron oxygen to form Zinc Oxide coat which protects iron from rusting
ii) Sacrificial protection or cathodic protection
maurice.mutuku answered the question on October 17, 2019 at 08:20
- Calculate the volume of oxygen gas used during the burning of magnesium (O = 16, molar gas volume = 24,000cm3 at room temperature)(Solved)
Calculate the volume of oxygen gas used during the burning of magnesium (O = 16, molar gas volume = 24,000cm3 at room temperature)
Date posted: October 17, 2019. Answers (1)
- How many chloride ions are present in 1.7g of magnesium chloride crystals?
(Avogadro’s constant = 6.0 x 1023, Mg = 24, Cl = 35.5)(Solved)
How many chloride ions are present in 1.7g of magnesium chloride crystals?
(Avogadro’s constant = 6.0 x 1023, Mg = 24, Cl = 35.5)
Date posted: October 17, 2019. Answers (1)
- When 1.675g of hydrated sodium carbonate was reacted with excess hydrochloric acid,
the volume carbon (IV) oxide gas obtained at room temperature and pressure was 150cm3).
Calculate...(Solved)
When 1.675g of hydrated sodium carbonate was reacted with excess hydrochloric acid,
the volume carbon (IV) oxide gas obtained at room temperature and pressure was 150cm3).
Calculate the number of moles of water of crystallization in one mole of hydrated sodium
carbonate:- (Na=23, H =1, C=12, O=16, MGV at R.T.P = 24000cm3)
Date posted: October 17, 2019. Answers (1)
- The equation of the formation of iron (III) chloride is
2Fe(s) + 3Cl2(g)------>2FeCl3
Calculate the volume of chlorine which will react with iron to form 0.5g of...(Solved)
The equation of the formation of iron (III) chloride is
2Fe(s) + 3Cl2(g)------>2FeCl3
Calculate the volume of chlorine which will react with iron to form 0.5g of Iron (III) chloride.
(Fe = 56 Cl=35.5). Molar gas volume at 298K = 24dm3)
Date posted: October 17, 2019. Answers (1)
- In a filtration experiment 25cm3 of a solution of Sodium Hydroxide containing 8g per
litre was required for complete neutralization of 0.245g of a dibasic acid....(Solved)
In a filtration experiment 25cm3 of a solution of Sodium Hydroxide containing 8g per
litre was required for complete neutralization of 0.245g of a dibasic acid. Calculate
the relative molecular mass of the acid (Na = 23.0, O = 16, H= 1)
Date posted: October 17, 2019. Answers (1)
- In an experiment magnesium ribbon was heated in air. The product formed was found to be heavier than the original ribbon. Potassium manganate (VII) was...(Solved)
In an experiment magnesium ribbon was heated in air. The product formed was found to be heavier than the original ribbon. Potassium manganate (VII) was on the other hand, heated in air and product formed was found to be lighter. Explain the differences on the observation made
Date posted: October 17, 2019. Answers (1)
- A fixed mass of gas occupies 200 cm3 at a temperature of 230c and a pressure of 740 mm Hg.
Calculate the volume of the gas...(Solved)
A fixed mass of gas occupies 200 cm3 at a temperature of 230c and a pressure of 740 mm Hg.
Calculate the volume of the gas at -250c and 790 mm Hg pressure.
Date posted: October 17, 2019. Answers (1)
- A gas occupies 5dm3 at a temperature of -270C and 1 atmosphere pressure. Calculate the volume occupied by the gas at a pressure of 2...(Solved)
A gas occupies 5dm3 at a temperature of -270C and 1 atmosphere pressure. Calculate the volume occupied by the gas at a pressure of 2 atmospheres and a temperature of 1270C
Date posted: October 17, 2019. Answers (1)
- The figure below shows two gases P and Q diffusing from two opposite ends 18 seconds after the experiment(Solved)
The figure below shows two gases P and Q diffusing from two opposite ends 18 seconds after the experiment
(a) Which of the gases has a lighter density?
(b) Given that the molecular mass of gas Q is 17, calculate the molecular mass of P
Date posted: October 17, 2019. Answers (1)
- Gas B takes 110 seconds to diffuse through a porous pot, how long will it take for the same amount of ammonia to diffuse under...(Solved)
Gas B takes 110 seconds to diffuse through a porous pot, how long will it take for the same amount of ammonia to diffuse under the same conditions of temperature and pressure?
(RMM of B = 34 RMM of ammonia = 17)
Date posted: October 17, 2019. Answers (1)
- Below are structures of particles. Use it to answer questions that follow. In each case only electrons in the outermost energy level are shown(Solved)
Below are structures of particles. Use it to answer questions that follow. In each case only electrons in the outermost energy level are shown
(a) Identify the particle which is an anion
(b) Choose a pair of isotopes. Give a reason
Date posted: October 17, 2019. Answers (1)
- A sample of Carbon (IV) Oxide takes 200 seconds to diffuse across a porous plug.
How long will it take the same amount of Carbon (II)...(Solved)
A sample of Carbon (IV) Oxide takes 200 seconds to diffuse across a porous plug.
How long will it take the same amount of Carbon (II) Oxide to diffuse through the same plug?(C=12, O=16)
Date posted: October 17, 2019. Answers (1)
- A fixed mass of gas occupies 200cm3 at a temperature of 23oC and pressure of 740mmHg.
Calculate the volume of the gas at -25oC and 780mmHg...(Solved)
A fixed mass of gas occupies 200cm3 at a temperature of 23oC and pressure of 740mmHg.
Calculate the volume of the gas at -25oC and 780mmHg pressure
Date posted: October 17, 2019. Answers (1)
- A factory produces Calcium Oxide from Calcium Carbonate as shown in the equation below:-(Solved)
A factory produces Calcium Oxide from Calcium Carbonate as shown in the equation below:-
What volume of Carbon (IV) Oxide would be produced from 1000kg of Calcium
Carbonate at s.t.p (Ca = 40, C = 12, O = 16, Molar gas volume at s.t.p = 22.4dm3)
Date posted: October 17, 2019. Answers (1)
- A gas occupied a volume of 250cm3 at -23ºC and 1 atmosphere. Determine its volume at 127ºC when pressure is kept constant.(Solved)
A gas occupied a volume of 250cm3 at -23ºC and 1 atmosphere. Determine its volume at 127ºC when pressure is kept constant.
Date posted: October 17, 2019. Answers (1)
- Gas V takes 10 seconds to diffuse through a distance of one fifth of a meter. Another gas W takes the same time to diffuse...(Solved)
Gas V takes 10 seconds to diffuse through a distance of one fifth of a meter. Another gas W takes the same time to diffuse through a distance of 10 cm. if the relative molecular mass of gas V is 16.0; calculate the molecular mass of W.
Date posted: October 17, 2019. Answers (1)
- State and explain the observation made when a piece of charcoal is dropped in a jar containing concentrated nitric (V) acid(Solved)
State and explain the observation made when a piece of charcoal is dropped in a jar containing concentrated nitric (V) acid
Date posted: October 17, 2019. Answers (1)
- The diagram below shows the heating curve of a pure substance. Study it and answer the questions that follow:(Solved)
The diagram below shows the heating curve of a pure substance. Study it and answer the questions that follow:
(a) Explain what happens between points A and C
(b) The substance under test is definitely not water; Give a reason for this
(c) What would happen to the melting point of this substance if it were contaminated with sodium chloride?
(d) What happens to the temperature between points B and C?
Date posted: October 16, 2019. Answers (1)
- Diamond and silicon (IV) Oxide have a certain similarity in terms of structure and bonding.
State it(Solved)
Diamond and silicon (IV) Oxide have a certain similarity in terms of structure and bonding.
State it
Date posted: October 16, 2019. Answers (1)
- Study the diagram below and use it to answer the questions that follow.(Solved)
Study the diagram below and use it to answer the questions that follow.
(a) State the observation made in the combustion tube.
(b) Write an equation for the reaction that took place in the combustion tube
(c) Give one use of P
Date posted: October 16, 2019. Answers (1)