How many moles of C3H8 (molar mass 44.09 g/mol) are represented by 5.31 g of this compound? Give your answer correctly to three significant digits.
How many C atoms are present in the sample of C3H8 with mass 5.31 g? Avogadro’s number is 6.022 × 1023. Enter your answer using scientific notation and to three significant digits.
- AshLv 71 month ago
moles of C3H8 = mass of C3H8 / molar mass of C3H8
= (5.31 g)/(44.09 g/mol)
= 0.120 mol
There are 3 'C' atoms in a molecule of C3H8
so moles of C = 3x 0.120 = 0.360 mol
number of C toms = moles of C atoms x Avogadro's number
= (0.360 mol)x (6.022 x 10²³ atoms/mol)
= 2.17 x 10²³