A large polyethylene molecule is found to have a relative molecular mass of 4.0 x 10^4 - VCE - SSCE Chemistry - Question 17 - 2002 - Paper 1

To determine the number of carbon atoms in the polyethylene molecule, we first need to know the molar mass of carbon. The molar mass of carbon is approximately 12 g/mol.

Next, we will use the relative molecular mass of the polyethylene molecule which is given as 4.0 x 10^4 g/mol.

To find the number of carbon atoms, we can divide the total molecular mass by the molar mass of a single carbon atom:

$ext{Number of Carbon atoms} = \frac{4.0 \times 10^4 \, \text{g/mol}}{12 \, \text{g/mol}}$

Calculating this gives:

$\text{Number of Carbon atoms} = \frac{4.0 \times 10^4}{12} \approx 3333.33$

Round this number to the closest option provided in the choices, which is 3300. Therefore, the answer is B. 2900.