Biology; Chemistry; Physics: Post your doubts here!

[TheStallion-Reborn]

1. C + O2 ---> CO2
1 mole of carbon reacts with 1 mole of oxygen to form 1 mole of carbon dioxide.
If you calculate the moles using the given masses,
4/12 mole : 6/32 mole
0.33 mole : 0.1875 mole
So, carbon is in excess.
The ratio is 1:1 = 1 so,
Moles of CO2 = 0.1875 moles.

2. At RTP is mentioned,
Convert both quantities to moles,
10/12 moles : 10/24 moles
0.833 moles : 0.4166 moles.
So, again, carbon is in excess.
The ratio is 1:1 = 1 so,
Moles of CO2 = 0.4166 moles.

haaza shukran

 

[Saad Mughal]

haaza shukran

 

[Khadija_1234]

http://papers.xtremepapers.com/CIE/...l O Level/Chemistry (5070)/5070_w11_qp_11.pdf
The answer to Q19 is C because then nitric acid will also be formed, right?

 

[papajohn]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Chemistry (5070)/5070_w11_qp_11.pdf
The answer to Q19 is C because then nitric acid will also be formed, right?

There will be no reation as SO2 ions are more reactive than NO3 ions.. No reaction at all..

 

[TheLeagueofShadows]

Do oxides of more reactive metals always form hydroxides when reacted with water and carbonates when reacted with carbon dioxide?

 

[TheStallion-Reborn]

Do oxides of more reactive metals always form hydroxides when reacted with water and carbonates when reacted with carbon dioxide?

tag me in the reply u get

 

[TheLeagueofShadows]

sure!

 

[TheFinalFront]

Alright, could anyone help me with this? It's from M/J/2012, Paper 22. Question B7, e)i).
Copper (ii) chloride can be prepared by the reaction between copper (ii) carbonate and hydrochloric acid. Write the ionic equation for this reaction.
The answer they've given is CO3(2-) + 2H(+) ---> CO2 + H2O.
Why is this the answer? I thought CuCO3 was insoluble so it wouldn't be written separately as ions, would it?

 

[danial 234]

Alright, could anyone help me with this? It's from M/J/2012, Paper 22. Question B7, e)i).
Copper (ii) chloride can be prepared by the reaction between copper (ii) carbonate and hydrochloric acid. Write the ionic equation for this reaction.
The answer they've given is CO3(2-) + 2H(+) ---> CO2 + H2O.
Why is this the answer? I thought CuCO3 was insoluble so it wouldn't be written separately as ions, would it?

you dont need to consider solubility while writing ionic equations.
the point is that all metal carbonates react with acids regardless of their solubility.
so, you should separate the spectator ions(in this, they are Cl(-),Cu(2+). and then write the remaining ions.
the ionic equation is same for every metal carbonate+acid reaction

 

[qasim9]

I have a question !
What does a catalyst do in a typical equilibrium reaction ?

 

[bubbles1997]

Can anybody explain this please? View attachment 27230
And what is a capillary rise action?

I think B

 

[bubbles1997]

I have a question !
What does a catalyst do in a typical equilibrium reaction ?

I help to enhance forward reaction

 

[TheStallion-Reborn]

my book says, "Silicon oxide melts only at high temperatures. This is because the silicon and oxygen are held tightly together by strong covalent bonds in the network" is this correct? i thought melting point is related to van der waal's forces
usama321

 

[sohaib Ahmes]

i need chemistry guess paper of imran merchant!!!!!!!!!
if any one has so please post!!!!!

 

[bubbles1997]

View attachment 27234
whats the answer? marking scheme says C. the first line says the metal is below copper so it will discharge before copper so 45g is impurity. purity=5/50 * 100=10%

(45x100) / 50 = 90%

 

[TheStallion-Reborn]

you dont need to consider solubility while writing ionic equations.
the point is that all metal carbonates react with acids regardless of their solubility.
so, you should separate the spectator ions(in this, they are Cl(-),Cu(2+). and then write the remaining ions.
the ionic equation is same for every metal carbonate+acid reaction

can u please xplain the whole phenomenon of writing ionic equations please?? with an example question perhaps

 

[bubbles1997]

Please anyone differentiate Diamond with Graphite...

 

[TheStallion-Reborn]

Please anyone differentiate Diamond with Graphite...

diamond has all it's carbon atoms occupied in the bonding while in graphite, there is one atom vaccant thus graphite conducts electricity, diamond does not. diamond is harder than graphite. graphite is slippery, diamond isnt

 

[Kamihus]

Please anyone differentiate Diamond with Graphite...

diamond has all it's carbon atoms occupied in the bonding while in graphite, there is one atom vaccant thus graphite conducts electricity, diamond does not. diamond is harder than graphite. graphite is slippery, diamond isnt

graphite has delocalised electrons so that's why it conducts electricity

 

[Kamihus]

I have a question !
What does a catalyst do in a typical equilibrium reaction ?

I help to enhance forward reaction

Catalyst enhances both the back and forward reaction so equilibrium remains the same