Question

Given the following chemical equation, if 50.1 grams of silicon dioxide is heated with excess carbon and 32.3 grams of silicon carbide is produced, what is the percent yield for this reaction?
SiO2 (s) + 3C (s) arrow SiC (s) + 2CO (g)
Answer

97%

75%

103%

48%

I believe this is 97, am I correct?

Answer 1

can you show your work?

Answer 2

hold on wrong work! lol

Answer 3

haha ok. i just wanna see your thought process ..and that you're not actually just guessing.

Answer 4

I thought it was 96 but checking back over my work I'm not sure - I think i made some errors. I know that the total mass of reactants = 60 + 36 = 96 grams

Answer 5

Because of that I presumed it would be 97% as that's closed but I realize I need to calculate the percent of yield. @aaronq

Answer 6

that's not how you do it.. at all :P

you need to convert the amounts in grams given to moles.

moles=\(\dfrac{m}{M}\)

then use the stoichiometric coefficients to build a ratio:

SiO2 (s) + 3C (s) arrow SiC (s) + 2CO (g),

\(\dfrac{n_{SiO_2}}{1}=\dfrac{n_{SiC}}{1}\)

since they're both 1, we can just say that the moles are equal.

SO, to find the percent yield, you divide the moles (or grams) actually produced, by the theoretical yield times 100%.

percent efficiency = \(\dfrac{mass \;obtained}{theoretical\; mass}*100\%\)

Answer 7

did u get it ? @Pumpkin890

Answer 8

can u tell me molar mass of SIO2 and SiC

Answer 9

Mass obtained? Would 50.1 be mass obtained and theoretical mass be 32.3?

Answer 10

nope :(

Answer 11

60.08 g/mol = SIO2
40.11 g/mol SiC

Answer 12

For the molar masses @chmvijay

Answer 13

ok now 60.08 gram SIO2 should produce 40.11 gram of SiC right according to equation
but 50.1 gram of SiO2 should give = 40.11*50.1 /60.08= 33.44 gram of SIC
but its forming only about 32.3 gram?
can u solve now

Answer 14

percent efficiency = 33.44/ 32.2 ∗100%
Is that right?

Answer 15

Ah! 103! Answer choice C Thank you @chmvijay

Answer 16

noo for 33.44 ----->100
for 32.3 gram=100*32.3/33.44 =

Answer 17

oOH OKAY. one more time here..

Answer 18

LOL