If a sample of Co2(CO)8 is found to contain 6*10^-2 mol of C atoms, how many grams of Co atoms are present?

Molar Mass (g/mol)

Co2(CO)8 - 341.95
Co atom - 58.933
C atom - 12.011
O atom - 15.999

Avaogadro's No.: 6.022*10^23

Do I need to use the 6*10^-2 mol of C atoms to find how many grams are in this sample of Co2(CO)8? Then from there find how many grams of Co atoms?

By the way, for clarification, what does it mean by "how many grams of X atoms?"

The answer is supposed to be: 0.89872825g

But I'd like an explanation on how to do this problem, thank you.

Each molecule contains 2 Co atoms and 8 C atoms. So, divide .06moles of C by 4 to get moles of Co

.06/4 = .015 moles of Co

.015mol * 58.933g/mol = 0.883995g

not quite your answer; check my math.

Why did you divide .06 moles by 4? Is it because there is a 8:4 ratio of C and Co?

Yes (actually a 2:8 ratio). 0.06 mols C x (2 Co atoms/8 mols C atoms) = 0.06 x (2/8) = 0.015 moles Co

I should point out that there is only 1 significant figure in 0.06 mol C atoms in the problem; therefore, an answer of 0.898728..... is inappropriate. The answer of 0.884 should be rounded to 0.9 g Co or 9E-1.

To determine the number of grams of Co atoms present in the sample of Co2(CO)8, you need to follow a two-step process.

Step 1: Find the number of moles of Co atoms in the sample.
To do this, you need to use the given information on the number of moles of C atoms in the sample and the molecular formula of Co2(CO)8. Let's go through the steps to calculate it:

First, you need to determine the molar mass of Co2(CO)8. Since the molar mass is given as 341.95 g/mol, this means that one mole of Co2(CO)8 weighs 341.95 grams.

Next, consider the molecular formula, Co2(CO)8. From this, we can note that there are 2 Co atoms in each Co2(CO)8 molecule.

Now, calculate the molar mass of a single Co atom. The molar mass of one Co atom is given as 58.933 g/mol.

Using the given information, we can set up a proportion to find the number of moles of Co atoms:
(6*10^-2 mol C) / (1 mol Co2(CO)8) = (x mol Co) / (2 mol Co2(CO)8)

Simplifying the proportion:
x = (6*10^-2 mol C) * (2 mol Co) / (1 mol Co2(CO)8)
x = 0.12 * (mol C/mol Co2(CO)8)

Step 2: Convert moles of Co atoms to grams.
Now that we have the number of moles of Co atoms, we can convert it to grams using the molar mass of Co atoms.

Multiply the number of moles of Co atoms by the molar mass of Co atoms:
Mass of Co = (x mol Co) * (molar mass of Co)
Mass of Co = (0.12 mol) * (58.933 g/mol)

So, the mass of Co atoms in the sample is 7.07196 g.

Therefore, the answer of 0.89872825 g appears to be incorrect. The correct answer should be 7.07196 g.