Sunday

January 25, 2015

January 25, 2015

Posted by **Jake** on Tuesday, February 5, 2008 at 8:35pm.

Given this information:

CxHyOz (s) + O2 (g) ----> CO2 + H20

given:

2.165 g of the unknown hydrocarbon

v = 1.868 L

P = 130.2 kPa

T = 65.0 degrees C

g of H2O = 1.818

1.18g/18.02 g/mol = .101 mol H20

.101/1.01 g/mol H2 = .1 X 2 = .2 g H

PV=nRT

n= PV/RT

(1.28 atm)(1.868 L)/(.0821 L atm/mol K)(338 K)

n= .0863 mols CO2

.0862 mols X 12.01 g/mol = 1.035g C

2.165 g -(.2 g + 1.035) = .93 g O

.2/ 1.01 = .198 mol

.93/16.00 = .581 mol

1.035/12.01 = .0862 mol

my mol ratios don't work out correctly

- AP Chemistry -
**drbob222**, Tuesday, February 5, 2008 at 10:13pm**Look for the BOLD below**

Given this information:

CxHyOz (s) + O2 (g) ----> CO2 + H20

given:

2.165 g of the unknown hydrocarbon

v = 1.868 L

P = 130.2 kPa

T = 65.0 degrees C

g of H2O = 1.818

a)find g H in hydrocarbon

1.18g/18.02 g/mol = .101 mol H20

.101/1.01 g/mol H2 = .1 X 2 = .2 g H

b)find mols CO2 in product then find g of C

PV=nRT

n= PV/RT

(1.28 atm)(1.868 L)/(.0821 L atm/mol K)(338 K)

n= .0863 mols CO2

.0862 mols X 12.01 g/mol = 1.035g C

c) find g O

2.165 g -(.2 g + 1.035) = .93 g O

d) find empirical formula of hydrocarbon

.2/ 1.01 = .198 mol

.93/16.00 = .581 mol**Here is your problem. This should be 0.0581. I didn't go through to see if this would clear up the problem but everything above is ok. good work and thanks for showing your work. It makes it easier to fine the error when you do it.**

1.035/12.01 = .0862 mol

my mol ratios don't work out correctly

- AP Chemistry -
**drbob222**, Tuesday, February 5, 2008 at 10:19pmI worked it through with the new numbers and I think the formula is C3H7O2 but check my work. The ratios seem to work ok with that one change. By the way, I would make a habit of placing the 0 in front of the decimal. It makes it unmistakable that .2 is actually 0.2 ir that 0.199 is correct. The decimal sometimes can get lost in .199.

**Answer this Question**

**Related Questions**

chemistry - Hi can you help me balance these equations? I did the first three ...

chemistry - Calculate the value of T delta S (KJ) of reaction for the equation ...

Chemistry - If someone could please be kind enough to see me through this ...

chemistry - Ok, I really need to know how to work problems like these so could ...

chem - the combustion of 1.83 grams of a compound which only contains C,H, and O...

Chemistry - I know mathematically I can write chemical reactions this way but in...

chem- plz check my work - 2. Given the following equation, C2H5OH(l) + 3 O2(g...

Chemistry - Calculate the value of Kp for the equation C(s)+CO2(g)<->2CO(g...

college math - Find the equation of the line with the given information. I know ...

Chem - Co2(g) ---> CO2(l) + heat This equation was given to me and asked why ...