Chemistry exam: Remember the question about a kid adding 1.35g (1 Viewer)

[Shoom]

Remember the question that said a kid added 1.35g of something to 1.35g of something and he got copper or calcium carbonate, calculate how much of the copper/calcium carbonate was produced.

What were the actual elements anyone remeber their answers?

 

[Timothy.Siu]

huh?

 

[Shoom]

1.35g sodium carbonate and 1.35g copper nitrate were both placed into 2 separate beakers of water. These substances were then mixed together. What is the mass of the copper carbonate is formed? (not exact wording. I cut out 90% of it)

Do this please, show working.

 

[Timothy.Siu]

1.35g sodium carbonate and 1.35g copper nitrate were both placed into 2 separate beakers of water. These substances were then mixed together. What is the mass of the copper carbonate is formed?

ok i'll try.
Na2CO3 + Cu(NO3)2 --->2NaNO3 + CuCO3

1.35/105.99=moles of sodium carbonate
1.35/187.57= moles of copper nitrate (limiting reagent?)
then u'll prolly get 1.35/187.57 moles of copper carbonate
wich is 1.35/187.57 x 123.56=0.889299994grams

i'm not sure...not too good with chem

 

[Shoom]

Ok, now figure out the masss of copper carbonate.

 

[Timothy.Siu]

Ok, now figure out the masss of copper carbonate.

yeah i did it edited it

 

[Shoom]

I hope your right that what I put, but since I put it has to be wrong ( I mean me get something right, impossible)

 

[Timothy.Siu]

I hope your right that what I put, but since I put it has to be wrong ( I mean me get something right, impossible)

lol, then it mite be right coz i put it

 

[Shoom]

If it is, I will be so happy I will smile. yes I rarely smile, I must be the most angry/dull person because I have a wrinkle on my forehead. Im noly 16 dammit, im gonna look like gordon ramsay when im 20!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Timothy.Siu]

If it is, I will be so happy I will smile. yes I rarely smile, I must be the most angry/dull person because I have a wrinkle on my forehead. Im noly 16 dammit, im gonna look like gordon ramsay when im 20!!!!!!!!!!!!!!!!!!!!!!!!!!!!

it cudn't hav been worth that many marks, BE HAPPY!!! SMILE!!

 

[Shoom]

I think it was worth 4 marks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:mad1: good this smiley has a wrinkle lol. :rofl:

 

[Timothy.Siu]

I think it was worth 4 marks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:mad1: good this smiley has a wrinkle lol. :rofl:

 

[Shoom]

Why did you use the Molar Mass of copper mitrate instead of the other thing? sorry for spelling im tired lol.

 

[zzzz12345]

1.35g sodium carbonate and 1.35g copper nitrate were both placed into 2 separate beakers of water. These substances were then mixed together. What is the mass of the copper carbonate is formed? (not exact wording. I cut out 90% of it)

Do this please, show working.

As stated before:
Na2CO3 + Cu(NO3)2 ---> CuCO3 + 2NaNO3

n(Na2CO3)= 1.35/105.99
= 0.0127 moles
n(Cu(NO3)2)=1.35/187.57
=0.007197
Therefore Cu(NO3)2 is the limiting reagent i.e. Copper nitrate will run out first in the reaction and thus no more product would be formed i.e. Copper Carbonate
Thus m(CuCO3)=0.007197 x (63.55+12.01+3 x 16)
=0.889 g (3dp)
You use the number of moles of copper nitrate because it is the limiting reagent (see explanation above). I suppose you can worry less now, if several people have gotten the same answer there is a high probability that you are right. Good Luck on your exams.

 

[bored of sc]

As stated before:
Na2CO3 + Cu(NO3)2 ---> CuCO3 + 2NaNO3

n(Na2CO3)= 1.35/105.99
= 0.0127 moles
n(Cu(NO3)2)=1.35/187.57
=0.007197
Therefore Cu(NO3)2 is the limiting reagent i.e. Copper nitrate will run out first in the reaction and thus no more product would be formed i.e. Copper Carbonate
Thus m(CuCO3)=0.007197 x (63.55+12.01+3 x 16)
=0.889 g (3dp)
You use the number of moles of copper nitrate because it is the limiting reagent (see explanation above). I suppose you can worry less now, if several people have gotten the same answer there is a high probability that you are right. Good Luck on your exams.

That's what I got.

 

[Shoom]

YYYYYYEEESSSSSSS!!!!!!!!!!!!!!!!!!!!

Thankyou all.

 

[David.Lai]

easy question....

mass= 0.0889g of copper carbonate..