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Half-life is the time taken for a given number of nuclides to decay to half its original number.
Belan answered the question on February 13, 2019 at 12:19
- 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)
- How long would 200cm3 of Hydrogen chloride take to diffuse through a porous plug if carbon(IV)oxide takes 200seconds to diffuse through?(Solved)
How long would 200cm3 of Hydrogen chloride take to diffuse through a porous plug if carbon(IV)oxide takes 200seconds to diffuse through?
Date posted: February 5, 2019. Answers (1)
- It takes 30 seconds for 100cm3 of carbon(IV)oxide to diffuse across a porous plate. How long will it take 150cm3 of nitrogen(IV)oxide to diffuse across...(Solved)
It takes 30 seconds for 100cm3 of carbon(IV)oxide to diffuse across a porous plate. How long will it take 150cm3 of nitrogen(IV)oxide to diffuse across the same plate under the same conditions of temperature and pressure?
(C=12.0,N=14.0=16.0)
Date posted: February 5, 2019. Answers (1)
- State Grahams law of diffusion and show its mathematical formula(Solved)
State Grahams law of diffusion and show its mathematical formula
Date posted: February 5, 2019. Answers (1)
- State Charles law and show its mathematical formula(Solved)
State Charles law and show its mathematical formula
Date posted: February 5, 2019. Answers (1)
- Calculate the pressure which must be applied to a fixed mass of 100cm3 of Oxygen for its volume to triple at 100000Nm-2.(Solved)
Calculate the pressure which must be applied to a fixed mass of 100cm3 of Oxygen for its volume to triple at 100000Nm-2.
Date posted: February 5, 2019. Answers (1)
- A fixed mass of gas at 102300Pa pressure has a volume of 25cm3. Calculate its volume if the pressure is doubled.(Solved)
A fixed mass of gas at 102300Pa pressure has a volume of 25cm3. Calculate its volume if the pressure is doubled.
Date posted: February 5, 2019. Answers (1)
- State Boyles law and show its mathematical formula(Solved)
State Boyles law and show its mathematical formula
Date posted: February 5, 2019. Answers (1)
- List two physical conditions that affect gas(Solved)
List two physical conditions that affect gas
Date posted: February 5, 2019. Answers (1)
- List and explain the 3 forms of matter(Solved)
List and explain the 3 forms of matter
Date posted: February 5, 2019. Answers (1)
- What is the difference between circulated and uncirculated hydrocarbon?(Solved)
What is the difference between circulated and uncirculated hydrocarbon?
Date posted: February 4, 2019. Answers (1)