Biology; Chemistry; Physics: Post your doubts here!

[Qasim Hafeez]

Dark Destination You got a CIE exam tomorrow? Then all the best. Please suggest some books for chem.

 

[Dark Destination]

so if we increase concentration , temperature, catalyst, the graph is steeper
and if we increase volume the volume of gas is more so graph is higher..
if we increase concentration does the volume of gas also increases so graph is both steeper and higher ?
and if we decrease volume and increase concentration the graph is steeper but at the same height ....
am i correct????

What do you mean?

 

[Laibaaa]

By adding Excess copper oxide to Hydrochloric acid, and then filtering out unreacted Copper oxide.
Then, heating the resultant solution, to evaporate of some of the water, and then allowing it to cool. Crystals of copper chloride can then be filtered off, and dried in the folds of a filter paper.

I dont know this properly
What do you do first, like you see that if its soluble or insoluble or what?
can you please explain how you arrived to how you used these reagents? D:

 

[Dark Destination]

Dark Destination You got a CIE exam tomorrow? Then all the best. Please suggest some books for chem.

Chemistry a course for O-Level, that Federal book. It's green colored.

And Thankyou.
Good Luck to you too, for whatever exam you have

 

[Dark Destination]

I dont know this properly
What do you do first, like you see that if its soluble or insoluble or what?
can you please explain how you arrived to how you used these reagents? D:

You just come up with two chemicals that you can mix together to form the required chemical.
Like, if you need COPPER CHLORIDE.

You need Something to provide CHLORIDE - HCL.
And something to provide COPPER.

Copper can't react with HCL, so you will have to use COPPER OXIDE, which is a base, and can react with acids.

Acids can react with any base to produce salt and water.

 

[Mahnoorfatima]

Ok. So when a carboxyilic acid reacts with metals every time 1/2 H2 would be released or it varies?

 

[Qasim Hafeez]

Chemistry a course for O-Level, that Federal book. It's green colored.

And Thankyou.
Good Luck to you too, for whatever exam you have

I have that book too. It's confusing for me. Maybe I am studying it wrong.

 

[exploded diper]

What do you mean?

for the graphs in which the volume of a gas made is plotted against time ... to measure the rate of reaction...

 

[Dark Destination]

I have that book too. It's confusing for me. Maybe I am studying it wrong.

Which chapters do you find confusing?

You need to read it with concentration. Otherwise, you won't get chemistry.

 

[Dark Destination]

for the graphs in which the volume of a gas made is plotted against time ... to measure the rate of reaction...

Concentration, Surface Area, Temperature and Catalyst effect the rate of reaction.

Why are you involving Volume? That has nothing to do with this.

Concentration x Volume = Moles.

If you increase the volume, the moles will increase, and the volume of gas given off will increase.
But if you increase the concentration, keeping the Volume constant, even them Moles would increase. In this case not only will the Volume of gas given off increase, but the rate of reaction will also increase.

 

[Qasim Hafeez]

Which chapters do you find confusing?

You need to read it with concentration. Otherwise, you won't get chemistry.

Acid bases. And other I get the concept, but I am confused with how to solve them , and which type of questions will come. Pastpapers scares me. Can you ask me some question like randomly from the first few chapters? that would be your revision too.

 

[FLRNAB]

so if we increase concentration , temperature, catalyst, the graph is steeper
and if we increase volume the volume of gas is more so graph is higher..
if we increase concentration does the volume of gas also increases so graph is both steeper and higher ?
and if we decrease volume and increase concentration the graph is steeper but at the same height ....
am i correct????

so if we increase concentration , temperature, catalyst, the graph is steeper -- Yes
and if we increase volume the volume of gas is more so graph is higher.. -- Yes

if we increase concentration does the volume of gas also increases so graph is both steeper and higher ? -- Steeper only
and if we decrease volume and increase concentration the graph is steeper but at the same height ....-- Less height
am i correct????

 

[Awesome12]

Explain plssssss
.View attachment 42225

***amd*** Awesome12

It is a transition metal, as it coloured

 

[Dark Destination]

Acid bases. And other I get the concept, but I am confused with how to solve them , and which type of questions will come. Pastpapers scares me. Can you ask me some question like randomly from the first few chapters? that would be your revision too.

Solve past papers, and check yourself with marking schemes. That is the best way to master past papers.

Unfortunately, i didn't give much time to this, i could have mastered all these subjects.

 

[Awesome12]

it is added till the "end point",which i think makes KMnO4 not in excess......
but do tell me how it is in excess if i am incorrect.......

No it is actually in excess. I did a past paper and in that there was a question as such, and the ans was KMnO4 was added in excess

 

[Mahnoorfatima]

1/2 H2 is produced everytime a carboxylic reacts with a metal????

 

[Laibaaa]

http://papers.xtremepapers.com/CIE/...l O Level/Chemistry (5070)/5070_s10_qp_42.pdf
Question number 6, the graph one.

The graph is steeper AND the volume at the end has doubled.
So shouldn't the answer have double the volume AND double the concentration as it is steeper too? :| Confused. Halhp.

P.s; how's everyones preparation going?

 

[Dark Destination]

1/2 H2 is produced everytime a carboxylic reacts with a metal????

What are you talking about?

 

[Dark Destination]

No it is actually in excess. I did a past paper and in that there was a question as such, and the ans was KMnO4 was added in excess

And what is the color change at end point?
It says Colorless to pink. :/ Why is Iron Sulfate colorless?

 

[Mahnoorfatima]

What are you talking about?

Dude when a carboxylic acid reacts with a metal like Na metal the product is salt and H2 gas right? So as the acid is a weak one, thus 1/2 H2 has to be produced EVERYTIME?