Chemo P5 tips

[Khadija.95]

unfortunately chem has weird scales but change it to scientific notation like 6*10^-4 and 12*106-4 so u can easily plot 6 and 12 then write at the end of x axis *10^-4 so examiner will know all ur values in decimals.

Thank you, yes that's what I was doing, but it's not very convenient. But a friend said something about not using I cm to 3, 6, 7 or 9 units. What does that mean? :/

 

[Mufasa]

thanx maaaan

 

[Zain Javaid]

hw to solve this log plxhelp

 

[Zain Javaid]

View attachment 43372
hw to solve this log plxhelp

 

[Mufasa]

During magnesium and hydrochloric acid experiment, to avoid loss of gas do not start the experiment by dropping a piece of Mg in the container of acid!!!
Rather, use a divided flask (I would appreciate it greatly if someone explains what that actually means) or place a test tube containing the magnesium metal in the solution and pull the string to start the reaction

If a syringe gives wrong volume, it could be because the syringe got stuck during the experiment

divided flask is sort of a flask connected to anohter flask or gas syringe to collect or measure gas obviously

 

[sachu06]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s13_qp_52.pdf
question number 1 (c) (iv)
please help me solve it!!
pleasee

 

[SomeStudent]

Thank you, yes that's what I was doing, but it's not very convenient. But a friend said something about not using I cm to 3, 6, 7 or 9 units. What does that mean? :/

These are odd scales and difficult to plot. Usually we take an even difference. Like one box may represent 1,2,4,5 or 10 etc

 

[Harsh Poddar]

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[TheSarcasticSoldier]

guys how do you make construction lines can't we directly read off two points for the gradient

 

[Dukeofwin]

View attachment 43372
hw to solve this log plxhelp

The marking scheme says You have to make 2 columns; In the first The reciprocal of Temperature in Kelvin(Since T is in Kelvin) and in the Second Column Log10 of reciprocal of time(log10 1/time).

However I also dont understand what the question says! It asks us to process 3 things in the table where the 1st and 3rd things are the same!

 

[Dukeofwin]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s13_qp_52.pdf
question number 1 (c) (iv)
please help me solve it!!
pleasee

Solubility= Mass/ Volume
1=x/0.250
*cross multiply we get*
MASS as 0.250g

Next
Moles= Mass/Mr(32+2+40)
Moles=0.250/74
Moles= 3.3x10^-3

Then
Conc= Moles/Volume
Conc= 3.3x10^-3/0.250dm^3
Conc=0.0135mol/dm^-3

 

[UsMAn_U7]

does any one have a list of all the available apparatus that we can use in our answers ? Plzz share

 

[chamiya]

guys how do you make construction lines can't we directly read off two points for the gradient

Its just an efficient and simple way to calculate the gradient and get credit without too many mistakes. If the graph is a straight line, take a reasonably long part and draw two perpendicular lines (parallel to the x and y axes) that meet the line. Read off the scales and note down the respective values. If it's a curve (rates of reaction), make sure to draw a tangent first (the tangent line JUST merely touches the curve; remember, at that point, the tangent is in the same direction of the curve, so take care). Then extrapolate the tangent until you have sufficient length to draw out the construction lines and find gradient.

 

[chamiya]

View attachment 43372
hw to solve this log plxhelp

The marking scheme says You have to make 2 columns; In the first The reciprocal of Temperature in Kelvin(Since T is in Kelvin) and in the Second Column Log10 of reciprocal of time(log10 1/time).

However I also dont understand what the question says! It asks us to process 3 things in the table where the 1st and 3rd things are the same!

They tell us to determine log(rate of reaction), reciprocal of Temperature, and rate of reaction. They mention that rate of reaction = reciprocal of time taken. Therefore, the column headings should look something like: log(1/t) [no units] , 1/T [K^-1] , 1/t [s^-1]

Note that log of something less than 1 is always negative, so don't be alarmed in future questions (they have mentioned it here though).

The first row should look like: -1.78 , 3.41*10^-3 , 0.0166

 

[zaidwaseem]

may june 2012.. Q1 part C..
we have to collect vapours in liquid and N2O in gas... basically 2 gases are evovlved.. wont we use fractional distillation??

 

[SomeStudent]

may june 2012.. Q1 part C..
we have to collect vapours in liquid and N2O in gas... basically 2 gases are evovlved.. wont we use fractional distillation??

Use a liebig condenser which goes to an air tight conical flask which has an outlet to a gas syringe for gas collection

 

[SomeStudent]

In the same question, it says we are to collect more than 10 cm^3 os N2O. How do we convert dm^3 to cm^3? The answer comes out to be very big

 

[zaidwaseem]

Use a liebig condenser which goes to an air tight conical flask which has an outlet to a gas syringe for gas collection

get that but how will we collect vapours as liquid in a beaker and N2O gas in the syringe at the same time????

 

[SomeStudent]

get that but how will we collect vapours as liquid in a beaker and N2O gas in the syringe at the same time????

Vapours will be condensed as water. Gas wont be so will go out to the outlet.

 

[zaidwaseem]

s

Vapours will be condensed as water. Gas wont be so will go out to the outlet.

so we'll connect a syringe at the top and a liebig condenser on the side>