Question

How many carbon atoms are in 15.6 kg of acetone? acetone is ch3coch3. the density of acetone is 1.30 g/ml?

Answer 1

Answer is: 4,859·10²⁶ atoms of carbon.
m(CH₃COCH₃) = 15,6 kg · 1000 g/kg = 15600 g.
n(CH₃COCH₃) = m(CH₃COCH₃) ÷ M(CH₃COCH₃).
n(CH₃COCH₃) = 15600 g ÷ 58 g/mol.
n(CH₃COCH₃) = 268,965 mol.
N(CH₃COCH₃) = n(CH₃COCH₃) · Na.
N(CH₃COCH₃) = 268,965 mol · 6,022·10²³ 1/mol.
N(CH₃COCH₃) = 1,619·10²⁶.
There is three atoms of carbon in one molecule of acetone, so:
n(C) = 3 · 1,619·10²⁶ = 4,859·10²⁶.

Answer 2

15.6 kg is equivalent to 15600 g
The molar mass of acetone is 58 g/mole
Therefore; 15600/58 = 269 moles
1 mole of acetone contains 3 × 6.022 × 10^23 atoms
Therefore, 269 moles of acetone would contain;
269 × 3× 6.022 ×10^23 atoms
= 4.86 ×10^26 atoms of carbon