Heat reaction calculation and formula

[esig]

I am in way over my head here and a little help would be very appreciated.

 

So I did an expiriment in school and am trying to write up the report but I am a little lost. I am supposed to set it all up in a table and calcutale the heat (sorry english is not my first language so I might not be clear on the correct chemistry terms). A few of theese would just be good to be clarified that I am doing the right thing, others I might a big nudge in the right direction.

 

So I had a reaction with distilled water an ammonium chloride (one of 5 reactions we made) I am suppsed to put in the table the initial chemicals/ reaction chemical formula and molemass. next one is the amount of chemicals in g per moles. NExt is the final soulution and formula ( in this area i generally suck). next I have the beginning and final temperatures. Next is the change in temperature (I'm just supposed to do inital-final right? or am I supposed to do high-low?? very confused on that one). Then there is +- delta temperatur ( am I supposed to put in the uncertainty in the measument here?) The last two are the heat of the chemical reaction in kJ and heat per moles kJ/mole ( I think i have the kJ one figured out but not the kJ/mole one)

 

 

I hope someone can help me before I go crazy

[studiot]

Was your coursework anything like these?

 

http://www.scienceforums.net/topic/85620-chemistry-coursework-2014/

 

http://www.scienceforums.net/topic/85585-gcse-coursework-2014/

[esig]

A bit similar but I am not making a graph. I am doing that for another part of the report though

http://oi57.tinypic.com/35d0zra.jpg

 

I included a print screen of the table, but it is in my language but then you get a better idea what I am trying to do

[studiot]

Well your experiment was more complete than the ones I linked.

 

Did you take the measurements youreselves or were they given to you?

 

First we need to settle the chemical formulae.

 

Can you write down the formulae for ammonium chloride, sodium chloride and water?

 

Can you then calculate the molar masses?

[esig]

I took the measurements myself

 

I have the formulas for the chemicals I used. NH4Cl, Na2CO3, NaHCO3, 2 M HCl, Fe (powder), 1 M CuSo4, 2 M CaCl2, 2 M NaOH, 2 M NaCO3, NaCl.

 

Molar mass is basicaly just formula mass right, find the elements in the periodic table, find the atomic mass and that is the same as molar mass right?

 

I did 5 reactions the first two were with distilled water and ammonium chloride and sodium carbonate.

3rd was the iron with the copper sulfate, the 4th sodium carbonate with calsium chloride and the last one was the effects of salt on ice.

 

I know the chemichals react with each other but truthfully I am really bad at what is happening, I am supposed to write down in the 4th colum what chemical was made and the formula.

IFor the first one I have H2O and NH4Cl and I am not sure how I am supposed to figure out the reactants (think that is the right word)

[studiot]

 

Molar mass is basicaly just formula mass right, find the elements in the periodic table, find the atomic mass and that is the same as molar mass right?

 

Yes that's correct.

 

Number of moles = Mass / molar mass

 

Molar mass = Sum of the individual atomic masses taking account of numbers of atoms

 

Mass concentration = total mass of substance per litre = total mass/ litres

 

Molar concentration = number of moles per litre = number of moles / litres

 

Have you studied balancing chemical equations yet?

 

I'm doing a chemical preparation at the moment (cooking the dinner) so I will keep going away and coming back.

 

So keep watch, others may also offer help meanwhile.

Edited October 19, 2014 by studiot

[esig]

I have studied balancing equations but I can never seem to get them right.

 

Well not never, sometimes they come out right but about 90% of the time they come out wrong

 

Good luck withe the chemical preparation

[Sensei]

I have studied balancing equations but I can never seem to get them right.

 

Well not never, sometimes they come out right but about 90% of the time they come out wrong

 

C'mon. It could be even in the first class of primary school. Could be learned parallel with adding on math..

 

Simply: quantity of atoms must match between left and right sides. Like in math.

 

f.e.

 

Fe + Cl₂ -> FeCl₃

 

On the left you have 1 Fe

On the left you have 2 Cl

On the right you have 1 Fe

On the right you have 3 Cl

 

Multiply right by 2. Now you have 2 Fe, 6 Cl

 

Then multiply left quantity of Fe by 2.

To have 6 Chlorines from Cl₂ you need multiply it by 3.

 

And finally there is

2 Fe + 3 Cl₂ -> 2 FeCl₃

 

On the left you have 2 Fe

On the left you have 6 Cl

On the right you have 2 Fe

On the right you have 6 Cl

 

It reminds me finding common denominator in math. You could as well replace all chemical element symbols by x,y,z unknowns and don't bother with them. f.e.

 

(1*x)+(2*y) = (x+3*y)

what is needed to make this equation to be true?

2*(1*x)+3*(2*y)=2*(x+3*y)

Edited October 21, 2014 by Sensei