Can someone please help me with these chemistry problems. Thanks.

Chemistry
Tutor: None Selected Time limit: 1 Day

I must show work to get credit.

1.What is the empirical formula of a substance composed of 56.6% potassium, 8.68% carbon, and 34.7% oxygen?

2. What is the empirical formula of a substance composed 49.89% strontium 13.67% carbon and 36.44% oxygen?

May 26th, 2015

1) Assume 100 grams of compound

then we have:

56.6g of Potassium

8.68g of Carbon

and 34.7g of Oxygen

using the atomic mas of each element we can find the number of moles of each element

K: 56.6g / 39.1 = 1.45 moles

C: 8.68g / 12 = 0.72 moles 

O: 34.7g / 2.17 moles


NOW, divide by the lower, in this case 0.72

K: 1.45 /0.72 = 2

C: 0.72 70.72 = 1

O: 2.177 0.72 =3

The formula of teh compound is: K2CO3

2) Assume 100 grams of compound

49.89 g Strontioun

13.67g carbon

36.44g Oxygen

using the atomic mas of each element we can find the number of moles of each element

Sr: 49.89 g /87.62 = 0.57 moles

C:13.67g / 12 = 1.14 moles 

O: 36.44g / 16=  2.28 moles

NOW, divide by the lower, in this case 0.57

Sr: 0.57 /0.57 = 1

C:1.14 /0.57 = 2

O: 2.28 /0.57 = 4

The empirical formula is: SrC2O4



May 26th, 2015

Thank you so much for your help.

May 26th, 2015

Hello, you just posted another question, I was answering when you change the type of question, I already have the answrr if you want, just select my bis in your question, I can explain very well the answer if you want. Best regards

May 27th, 2015

Are you studying on the go? Check out our FREE app and post questions on the fly!
Download on the
App Store
...
May 26th, 2015
...
May 26th, 2015
Dec 5th, 2016
check_circle
Mark as Final Answer
check_circle
Unmark as Final Answer
check_circle
Final Answer

Secure Information

Content will be erased after question is completed.

check_circle
Final Answer