Physics, Chemistry and Biology: Post your doubts here!

[masterex567]

A is the answer
500/24=20.8333...
20.833*4/5 =16.677...
16.677... * 24= 400 cm3

marking scheme says C?

 

[Saad the Paki]

marking scheme says C?

hmmm.... C seems to be a bit weird..! I got A as the answer as well...
what year and which variant is this?

 

[Mr.Physics]

It's C guyzz !! It's really easy !! Just a bit tricky !!
Equation : 2C2H2 + 5O2 ----- 4CO2 + 2H2O

Volumes used : 20 cm3 + 500cm3 ------ ? + ?

Volumes actually
reacted : 20 cm3 + 50cm3 ---------- ? + ?

Volume of Oxygen reacted is 50 cm3 because according to the chemical equation , 2 of C2H2 requires 5 of O2 , so 20 of C2H2 requires 50 of O2 !!

NOW ACCORDING TO EQUATION :

1 cm3 + 2.5 cm3 ---------- 2 cm3 + 1 cm3
20cm3 + 50cm3 --------- 40cm3 + 20 cm3

Total volume of gases remaining : ( 500 - 50) + 40 = 490 cm3 !!!

The main part of the question to understand is that O2 was in excess !!!

 

[Saad the Paki]

It's C guyzz !! It's really easy !! Just a bit tricky !!
Equation : 2C2H2 + 5O2 ----- 4CO2 + 2H2O

Volumes used : 20 cm3 + 500cm3 ------ ? + ?

Volumes actually
reacted : 20 cm3 + 50cm3 ---------- ? + ?

Volume of Oxygen reacted is 50 cm3 because according to the chemical equation , 2 of C2H2 requires 5 of O2 , so 20 of C2H2 requires 50 of O2 !!

NOW ACCORDING TO EQUATION :

1 cm3 + 2.5 cm3 ---------- 2 cm3 + 1 cm3
20cm3 + 50cm3 --------- 40cm3 + 20 cm3

Total volume of gases remaining : ( 500 - 50) + 40 = 490 cm3 !!!
The main part of the question to understand is that O2 was in excess !!!

Allrriigghht...!!! Nice one..!
U saw u're Mr.Physics but u seem equally good at chemistry too..!

 

[Mr.Physics]

Allrriigghht...!!! Nice one..!
U saw u're Mr.Physics but u seem equally good at chemistry too..!

Haha lol I named my account as Mr.Physics coz I like Physics !! However Im done with it !!

 

[Mr.Physics]

Allrriigghht...!!! Nice one..!
U saw u're Mr.Physics but u seem equally good at chemistry too..!

Hey will this be ur first CIEs ??

 

[Saad the Paki]

Hey will this be ur first CIEs ??

Yup..!

 

[Muaaz Iqbal]

Is anyone Having IGCSE Biology study guide

 

[Mr.Physics]

Is anyone Having IGCSE Biology study guide

Lol yahan pe upload nhi ho sakti !! Fb main mediafire ka link send kia hay tumhay !! Check kr lay !!

 

[Muaaz Iqbal]

Lol yahan pe upload nhi ho sakti !! Fb main mediafire ka link send kia hay tumhay !! Check kr lay !!

Tu ne Jo send kiya tha Wohi Download kar Liya hay.. Btw Agr Mediafire pewh Upload Kar diya Hay tu Send kar diena.

 

[lina1999]

Can u help please
Chemistry doubt
I need an explanation about the preparation of soluble and insoluble salts including all the titration, neutralization
And in what cases can we use them

 

[Saad the Paki]

Sooo.. a little bit of help needed..
a)(i) can be either burette or measuring cylinder?
a)(ii) i have no clue..

 

[jj1234]

Sooo.. a little bit of help needed..
a)(i) can be either burette or measuring cylinder?
a)(ii) i have no clue..

a)i) pippet...because exact 25

 

[Muaaz Iqbal]

Can u help please
Chemistry doubt
I need an explanation about the preparation of soluble and insoluble salts including all the titration, neutralization
And in what cases can we use them

This is All what you need

 

[Saad the Paki]

a)i) pippet...because exact 25

Mark scheme says measuring cylinder... ! :/

 

[Muaaz Iqbal]

Mark scheme says measuring cylinder... ! :/

It's Easy Measuring cylinder beacuse we have to "MEASURE" the dillute nitric acid

 

[Mr.Physics]

Sooo.. a little bit of help needed..
a)(i) can be either burette or measuring cylinder?
a)(ii) i have no clue..

a ) i ) It should be measuring cylinder because we aren't told to measure "exactly".
a) ii) Because carbonates react at room temperature and so don't require heat !!

 

[Muaaz Iqbal]

Answer of C..

 

[Muaaz Iqbal]

Secondly I'm facing Problem in Chem paper 6 And it's Hard for me to attempt Question Like these in Attachment
Guys you got any tip for that...

 

[jj1234]

Secondly I'm facing Problem in Chem paper 6 And it's Hard for me to attempt Question Like these in Attachment
Guys you got any tip for that...

Attachment 2..which q?
Attachment 1..umm i did GCE O'level..