# Homework Help: Basic Chemistry

1. Oct 12, 2011

### domtar

1. The problem statement, all variables and given/known data

The total number of atoms in 1.00 g of CaCO3 (MM = 100.0 g/mol) is:

3. The attempt at a solution

My solution: 1.00 / 100.0 = 0.01, then 0.01 x 6.022x10^23 = 6.022x10^21 atoms.

However, the correct answer is 3.01 x 10^22. How was my approach wrong and did I miss any steps? Any help much appreciated.

2. Oct 12, 2011

### gabriels-horn

5 atoms in the molecule of CaCO3

3. Oct 12, 2011

### domtar

I don't think that's the conclusion I was suppose to arrive at... I'm unsure about the sort of calculations.

4. Oct 13, 2011

### Staff: Mentor

Gabriels-horn is perfectly right - you are asked about total number of atoms, so far you have (correctly) calculated number of molecules.

One molecule of CaCO3 is made of one Ca atom, one C atom and 3 O atoms - five atoms total.

How many atoms (in total) in 3 molecules of CaCO3?

How many atoms (in total) in 6.022x1021 molecules of CaCO3?