Sunday

November 23, 2014

November 23, 2014

Posted by **Jessica** on Saturday, January 15, 2011 at 2:19am.

a) how many carbon atoms does the sample contain?

b) what is the total mass of the sample?

- chemistry -
**Dr Russ**, Saturday, January 15, 2011 at 2:33amFrom the formula (C3H8) [please use capital letters for element symbols] we see that there are 3 C atoms for 8 H atoms. If we had 16 H atoms there would be 6 C atoms for example.

Thus is there are 3.84x10^24 H atoms.

a) then there are (3/8)x3.84x10^24 C atoms

b) there are a couple of ways to do this.

If the sample contains 3.84x10^24 H atoms and each molecule contains 8 H atoms then there are 3.84x10^24/8 molecules of propane. Each mole contains 6 x 10^23 molecules so there are

3.84x10^24/(8 x 6 x 10^23 )moles

the molar mass of propane is

(3x12)+(8x1) g mole^-1

hence find the mass as

mass= molar mass x number of moles

**Answer this Question**

**Related Questions**

CHEMISTRY - A sample of C3H8 has 2.64 x 10^24 atoms. How many carbon atoms does...

chemistry - A sample of propane C3H8 contains 13.5 moles of carbon atoms how ...

Chemistry - A sample of propane,C3H8, contains 14.4 moles of carbon atoms. How ...

Chemistry - A sample of C3H8 has 2.64 x 10^24 atoms. How many carbon atoms does...

chemistry - A sample of propane, \rm C_3H_8, contains 12.8 moles of carbon atoms...

chemistry - a sample of glucose, c6h12o6 contains 2.03*10^21 atoms of carbon. (a...

Chemistry - A sample of toluene, C7H8 has a mass of 74.5 g. How many moles of ...

chemistry - You have a 12.01 g sample of carbon. The average mass of a carbon ...

Chem - If you have a 12.01g sample carbon. What would be the average mass of a ...

chemysteryyy!!!! - Rubbing Alchol often contains propanol, C3H7OH. Suppose that ...