Question

Marble (calcium carbonate) reacts with hydrochloric acid solution to form calcium chloride solution, water, and carbon dioxide. What is the percent yield of carbon dioxide if 3.65 g of the gas is collected when 10.0 g of marble reacts?

Answer 1

\[CaCO_3+2HCl \rightarrow CaCl_2+H_2O+CO_2\]
You have to find which is limiting first, we take 10g of marbles
\[10g~marbles \times \frac{1~mol~marbles}{40+12+3(16)g~marbles} \times \frac{1~mol~CO_2}{1~mol~marbles}=0.4~mol~CO_2\]
Then
\[0.4~mol~CO_2 ~\times \frac{12+2(16)g~CO_2}{1~mol~CO_2}=17.6g~of~CO_2\]
Based on theoretical calculations, you should get 17.6g of CO2, but it turns out that you only have 3.65g of CO2 collected, so,
\[\frac{3.65g}{17.6g}\times 100=20.7 ~percent\]

Answer 2

how can i find the limiting?

Answer 3

sam

Answer 4

help

Answer 5

it's conversion...
- mass of marble to moles of marble
- moles of marble to moles of carbon dioxide
- moles of carbon dioxide to mass of carbon dioxide

sometimes you might be done here but the question also asks for percent yield, so you calculate that too (actual yield / theoretical yield)

Answer 6

The problem says that a certain amount of marble reacts and says nothing about the amount of hydrochloric acid, so we can assume there is enough of the acid to react with the whole amount of marble. Thus, the amount of marble limits the amount of carbon dioxide produced.

Answer 7

3.65g of CO2 is the limiting reagent because its lower than the theoretical yield which is
17.6g of CO2

Answer 8

...not because it is less than theoretical yield (actual yield will almost always be smaller than theoretical yield because few reactions are perfectly efficient)

Answer 9

so the acutal yield is 3.65 and the T.Y is mole of CaCO3 x atomic weight of CO2?

Answer 10

CaCO3 x atomic weight of CO2 but just because the moles of CaCO3 and CO2 in this equation are the same

Answer 11

is the atomic weight of CO2 is 43.99?

Answer 12

i got 83%. am I right?

Answer 13

AW: yes, depending on the precision of the numbers you are using (about 44)

%Y: Sam seems right

Answer 14

83 %?

Answer 15

where are you getting 83%?

Answer 16

from 3.65/4.399x100

Answer 17

3.65/(.4*43.99)

Answer 18

where did the 4 came from?

Answer 19

no that's it... the 0.4 is moles of CO2

Answer 20

from the equation above where did this came from >
40+12+3(16)g marbles

Answer 21

oh sorry i thought that was 2(16), now i get it

Answer 22

cool

Answer 23

thanks

Answer 24

you're welcome

Answer 25

thanks for the medal. go chem! :-)