Chemistry, 26.07.2019 14:30 cookie1701

Silicon dioxide reacts with carbon upon heating to produce silicon carbide (sic) and carbon monoxide. sio2(s) + 3c(s) → sic(s) + 2co(g) a. what mass of carbon is required to react completely with 15.70 g of sio2? b. when 152 g of sio2 reacts with excess carbon, what mass of sic is produced? c. if 42.2 g of co were produced by this reaction, what mass of carbon must have reacted?

Answers: 1

Show answers

Answers

Q1)
the balanced equation is ;
SiO₂(s) + 3C(s) → SiC(s) + 2CO(g)
stoichiometry of SiO₂ to C is 1:3
mass of SiO₂ reacted - 15.70 g
molar mass of SiO₂ - 60 g/mol
Number of SiO₂ moles that reacted - 15.70 g / 60 g/mol = 0.26 mol
Then the number of C moles that reacted - 0.26 mol x3 = 0.78 mol
Mass of C required - 0.78 mol x 12 g/mol = 9.36 g

Q2)
Stoichiometry of SiO₂ to SiC is 1:1
SiO₂ is the limiting reactant, therefore amount of product formed depends on amount of SiO₂ reacted.
Number of SiO₂ moles reacted - 152 g/ 60 g/mol = 2.53 mol
Therefore number of SiC moles formed - 2.53 mol
molar mass of SiC - 40 g/mol
Mass of SiC formed - 2.53 mol x 40 g/mol = 101.2 g

Q3)
Stoichiometry of C to CO is 3:2
Molar mass of CO - 28 g/mol
Number of CO moles formed - 42.2 g / 28 g/mol = 1.5 mol
2 mol of CO formed when - 3 mol of C reacts
When 1.5 mol of CO are formed - 3/2 x 1.5 mol = 2.25 mol of C reacted
therefore 2.25 mol of C reacted
Mass of C reacted - 2.25 mol x 12 g/mol = 27 g

Answer from: Quest

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

Answer from: Quest

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally

Other questions on the subject: Chemistry

Chemistry, 22.06.2019 06:30, dpchill5232

Suppose a lab group reports a ppercent yield of sand of 105. is it really possible to collect more sand than was originally represented? what is the possible explanation for the extra product?

Answers: 2

continue

Chemistry, 22.06.2019 11:00, justarando

Which element would mostly likely have an electron affinity measuring closest to zero

Answers: 3

continue

Chemistry, 22.06.2019 11:40, tatemelliott

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.

Answers: 3

continue

Chemistry, 22.06.2019 12:20, tenleywood

The yearly amounts of carbon emissions from cars in belgium are normally distributed with a mean of 13.9 gigagrams per year and a standard deviation of 5.8 gigagrams per year. find the probability that the amount of carbon emissions from cars in belgium for a randomly selected year are between 11.5 gigagrams and 14.0 gigagrams per year. a. 0.340 b. 0.660 c. 0.167 d. 0.397

Answers: 2

continue

You know the right answer?

Silicon dioxide reacts with carbon upon heating to produce silicon carbide (sic) and carbon monoxide...