Formaldehyde has the formula CH2O. How many molecules are there in 0.11 g of formaldehyde?

Answer 1

First calculate the moles of methanal(formaldehyde)

moles(HCHO)= 0.11 / (30; Mr of ethanal) = 0.0036666...

Remember the Avogadro Number. (6.022 x 10^(23)) is the number of molecules/atoms in ONE mole .

Hence in 0.0036666 moles there are

0.0036666... X 6.022 x 10(23) = 2.20806 x 10^(21) molecules in 0.11 g of methanal.

NB ; In modern IUPAC chemical nomenclature formaldehyde is named as METHANAL.

NNB Note the 'A' instead 'o' in the name,

NNNB The aldehyde formula is written as HCHO ; ( Ethanal would be CH3CHO). The arrangement of the letters in the formula is XCHO

Hope that helps!!!!