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- A hydrocarbon was found to contain 92.3% carbon and the remaining Hydrogen. If the molecular mass of the compound is 78, determine the molecular formula(C=12.0,...(Solved)
A hydrocarbon was found to contain 92.3% carbon and the remaining Hydrogen. If the molecular mass of the compound is 78, determine the molecular formula(C=12.0, H =1.0)
Date posted: February 15, 2019. Answers (1)
- 1.60g of an oxide of Magnesium contain 0.84g by mass of Magnesium.
Determine its empirical formula(Mg = 24.0, 16.0)(Solved)
1.60g of an oxide of Magnesium contain 0.84g by mass of Magnesium.
Determine its empirical formula(Mg = 24.0, 16.0)
Date posted: February 15, 2019. Answers (1)
- Calculate the mass of Oxygen used to react with copper(Solved)
Calculate the mass of Oxygen used to react with copper
Date posted: February 15, 2019. Answers (1)
- 25 cm3 of carbon(II)oxide diffuses across a porous plate in 25 seconds. How long will it take 75 cm3 of Carbon(IV)oxide to diffuse across the...(Solved)
25 cm3 of carbon(II)oxide diffuses across a porous plate in 25 seconds. How long will it take 75 cm3 of Carbon(IV)oxide to diffuse across the same plate under the same conditions of temperature and pressure. (C=12.0,0=16.0)
Date posted: February 15, 2019. Answers (1)
- How long would 200 cm3 of Hydrogen chloride take to diffuse through a porous plug if carbon(IV)oxide takes 200 seconds to diffuse through?(Solved)
How long would 200 cm3 of Hydrogen chloride take to diffuse through a porous plug if carbon(IV)oxide takes 200 seconds to diffuse through?
Date posted: February 15, 2019. Answers (1)
- How does the use of manganese (IV) oxide in the laboratory preparation of chlorine gas differ from its use in the laboratory preparation of hydrogen...(Solved)
How does the use of manganese (IV) oxide in the laboratory preparation of chlorine gas differ from its use in the laboratory preparation of hydrogen gas?
Date posted: February 13, 2019. Answers (1)
- Explain the following:
(i)Nitric acid is stored in dark brown bottles.
(ii)Alkalis are not stored in Aluminium containers or bottles.(Solved)
Explain the following:
(i)Nitric acid is stored in dark brown bottles.
(ii)Alkalis are not stored in Aluminium containers or bottles.
Date posted: February 13, 2019. Answers (1)
- An element Q reacts with dilute acids but not with cold water. Element R does not react with dilute acids.Element S displaces element P from...(Solved)
An element Q reacts with dilute acids but not with cold water. Element R does not react with dilute acids. Element S displaces element P from its oxides. P reacts with cold water. Arrange the four metals in order of their reactivity starting with the most reactive.
Date posted: February 13, 2019. Answers (1)
- Give three uses of copper metal.(Solved)
Give three uses of copper metal.
Date posted: February 13, 2019. Answers (1)
- Define the term 'half life' as used in radioactivity.(Solved)
Define the term 'half life' as used in radioactivity.
Date posted: February 13, 2019. Answers (1)
- A form 1 student was supplied with a colourless liquid suspected to be water.
(i)Describe one chemical test that could be carried out to show that...(Solved)
A form 1 student was supplied with a colourless liquid suspected to be water.
(i)Describe one chemical test that could be carried out to show that the liquid was water.
(ii)How could it have been shown that the liquid was pure water?
Date posted: February 13, 2019. Answers (1)
- The use of materials of lead in roofing and in water pipes is being discouraged.
State
(i)Two reasons why these materials have been used in the past.
(ii)One...(Solved)
The use of materials of lead in roofing and in water pipes is being discouraged.
State
(i)Two reasons why these materials have been used in the past.
(ii)One reason why their use is being discouraged.
Date posted: February 13, 2019. Answers (1)
- State the observations made when iodine is heated in a boiling tube.(Solved)
State the observation made when iodine is heated in a boiling tube.
Date posted: February 13, 2019. Answers (1)
- Describe how a detergent functions in cleaning.(Solved)
Describe how a detergent functions in cleaning.
Date posted: February 13, 2019. Answers (1)
- State three factors that influence ionization energy.(Solved)
State three factors that influence ionization energy.
Date posted: February 13, 2019. Answers (1)
- Give three applications of calcium oxide.(Solved)
Give three applications of calcium oxide.
Date posted: February 13, 2019. Answers (1)
- An oxide of copper in a porcelain boat was reduced by a stream of hydrogen. The results obtained were as follows.
Mass of porcelain boat=4.5g
Mass of...(Solved)
An Oxide of copper in a porcelain boat was reduced by a stream of hydrogen. The results obtained were as follows.
Mass of porcelain boat=4.5g
Mass of boat + Oxide=6.40g
Mass of boat + Copper=6.02g
(i)Determine the empirical formula of the oxide.
(ii)If the relative formula mass of the oxide is 80,determine its chemical formula.
(Cu =64, O=16)
Date posted: February 13, 2019. Answers (1)
- Calculate the number of atoms present in:(Avogadros constant L = 6.0 x 10 23) 0.23 g of dilute sulphuric (VI)acid(Solved)
Calculate the number of atoms present in:(Avogadros constant L = 6.0 x 10 23) 0.23 g of dilute sulphuric (VI)acid
Date posted: February 5, 2019. Answers (1)
- What is the Avogadro's Constant?(Solved)
What is the Avogadro's Constant?
Date posted: February 5, 2019. Answers (1)
- Oxygen gas takes 250 seconds to diffuse through a porous diaphragm. Calculate the molar mass of gas Z which takes 227 second to diffuse.(Solved)
Oxygen gas takes 250 seconds to diffuse through a porous diaphragm. Calculate the molar mass of gas Z which takes 227 second to diffuse.
Date posted: February 5, 2019. Answers (1)