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Example 1 : A general purpose cleaner is made up as follows:
foaming agent 10 %
ammonia 5%
bleaching agent 12%
Binding agent 10%
Detergent 19
insoluble substances 44%
Outline with expiremental methods how would you show that the cleaner contains 44% insoluble mterials
Ans: Weigh 100g of cleaner using balance
Transfer sample to a beaker
add 50 cm^2 of distilled water using measuring cylinder
Stirr the mix using glass rod
Filter the mixture
wash and dry and weigh residue
mass of residue obtained will be 44g
Example 2:A farmer needs to test and compare the acidity of two samples of soil.Outlinw how the farmer should carry out the tests?
Ans: Weigh 2 samples of different soils using blance
crush each sample
transfer each sample to a beaker
add equal amount of distillef water to each sample
filter the mixture
add universal indicator to each filtrate from each sample
observe colour change ( If red>Strong If orange>Weak
Example 3 : Concrete is made of cement, sand and small stones. Outline an expirment to find out the compostion of a sample of concrete .
Ans: Weigh 5o gr of concrete
Add excess hcl to the sample
stirr the mixture
filture the mixture
sands and stones are optained as a residue
Caco3 due to the reaction with acid forms CaCl2 which is obtained as a filtrate.
Example 4:Make a plan to coat a copper ring with gold ( Electroplating, It's simple)
You need to draw the electroplating device first, (Cathode=Cu ring, Anode= Au)
then you must mention : Clean Cu ring with sand paper to remove impurities
Dissolve AuNo3 crystals in distilled water to make Aq AuNo3
Connect as shown ( Diagram)
Afer some time the red colur of the Cu ring will turn into yellow
Example 5: You are provided with a measuring cylinder, a beaker , a thermometer, Spirit burner, balance, fuel, stand, copper can
Plan an expirment to investigate wich alcohol, methanol or ethanol, produces more energy?
Ans= Weigh two spirit burner of the same mass
put each one under a copper can
add the same volume of water to each can
Suspend thermometer in each metal can and measure the initial temp
burn each fuel for a minute
record rise in temp in each case
Thermometer which record higher temp indicates the better fuel .
Example 6 : Plan an expirement you could do to prove that there is only two yellow substances are present in a lemon drink ( or equivalent)
Ans= CHROMOTOGRAPHY( Simple and easy)
* I hope this helps, Good luck all :wink:
foaming agent 10 %
ammonia 5%
bleaching agent 12%
Binding agent 10%
Detergent 19
insoluble substances 44%
Outline with expiremental methods how would you show that the cleaner contains 44% insoluble mterials
Ans: Weigh 100g of cleaner using balance
Transfer sample to a beaker
add 50 cm^2 of distilled water using measuring cylinder
Stirr the mix using glass rod
Filter the mixture
wash and dry and weigh residue
mass of residue obtained will be 44g
Example 2:A farmer needs to test and compare the acidity of two samples of soil.Outlinw how the farmer should carry out the tests?
Ans: Weigh 2 samples of different soils using blance
crush each sample
transfer each sample to a beaker
add equal amount of distillef water to each sample
filter the mixture
add universal indicator to each filtrate from each sample
observe colour change ( If red>Strong If orange>Weak
Example 3 : Concrete is made of cement, sand and small stones. Outline an expirment to find out the compostion of a sample of concrete .
Ans: Weigh 5o gr of concrete
Add excess hcl to the sample
stirr the mixture
filture the mixture
sands and stones are optained as a residue
Caco3 due to the reaction with acid forms CaCl2 which is obtained as a filtrate.
Example 4:Make a plan to coat a copper ring with gold ( Electroplating, It's simple)
You need to draw the electroplating device first, (Cathode=Cu ring, Anode= Au)
then you must mention : Clean Cu ring with sand paper to remove impurities
Dissolve AuNo3 crystals in distilled water to make Aq AuNo3
Connect as shown ( Diagram)
Afer some time the red colur of the Cu ring will turn into yellow
Example 5: You are provided with a measuring cylinder, a beaker , a thermometer, Spirit burner, balance, fuel, stand, copper can
Plan an expirment to investigate wich alcohol, methanol or ethanol, produces more energy?
Ans= Weigh two spirit burner of the same mass
put each one under a copper can
add the same volume of water to each can
Suspend thermometer in each metal can and measure the initial temp
burn each fuel for a minute
record rise in temp in each case
Thermometer which record higher temp indicates the better fuel .
Example 6 : Plan an expirement you could do to prove that there is only two yellow substances are present in a lemon drink ( or equivalent)
Ans= CHROMOTOGRAPHY( Simple and easy)
* I hope this helps, Good luck all :wink:
