Ocr chemistry a as - someone plzzzz explain 1.1-9 moles and equations to me

Hey guys
I am new to the student room ..I know it says i joined last year but I never actually used it loool... so I am sorry if I am doing any thing wrong... for example I am posting this thread in the wrong section etc. but I hav my mock exam tomorrow and I am stuck on
1.1 - 9 Moles and reactions

I seriously do not get how to deduce the quantities of reactants and products from balanced equations :frown:

speciall the bit where it says
amount in equation
amount required

How do u find out the amounts required :s-smilie:

plz explain to me the step by step procedure

THANKS A LOT IN ADVANCE GUYS :smile:

Reply 1

soup

11

Well let's say we have the combustion of methane:

CH_4 + 2O_2 -> CO_2 + 2H_2O

From the equation we see that 1 mole of methane reacts with 2 moles of oxygen which then produces 1 mole of carbon dioxide and 2 moles of water.

If we had 16g of methane we would require 64g of oxygen to produce 48g of

CO_2

and 36g of water

But if we had 4g of methane we would require 16g of oxygen to produce 12g of

CO_2

and 9g of water
All i've done is divide all values by 4

Hopefully this explanation is what you are after

Reply 2

godknows

OP

Original post by soup

Well let's say we have the combustion of methane:

CH_4 + 2O_2 -> CO_2 + 2H_2O

From the equation we see that 1 mole of methane reacts with 2 moles of oxygen which then produces 1 mole of carbon dioxide and 2 moles of water.

If we had 16g of methane we would require 64g of oxygen to produce 48g of

CO_2

and 36g of water

But if we had 4g of methane we would require 16g of oxygen to produce 12g of

CO_2

and 9g of water
All i've done is divide all values by 4

Hopefully this explanation is what you are after

helloo thanks for your reply :smile:

basically let me givE u an example of a type of question related to this topic

q1) 2.529 g oF MgCO3 reacts with an eXcess of HNO3
(i) What volume of CO2 measured at RTP, is formed?
(ii) The final volume of the solution is 50.0 cm3. what is the concentration, in mol dm-3, of Mg(NO3)2 formed ?

I AM TOTALLY LOST :frown:

Original post by godknowsprerna

helloo thanks for your reply :smile:

basically let me givE u an example of a type of question related to this topic

q1) 2.529 g oF MgCO3 reacts with an eXcess of HNO3
(i) What volume of CO2 measured at RTP, is formed?
(ii) The final volume of the solution is 50.0 cm3. what is the concentration, in mol dm-3, of Mg(NO3)2 formed ?

I AM TOTALLY LOST :frown: