Question

What is the mass (in grams) of 9.06 * 10²⁴ molecules of methanol (CH₃OH)?

Answer 1

Molar mass of methanol , CH3OH=CH4O = At.mass of C + ( 4xAt.mass of H ) + At.mass of O

                                                             = 12 + ( 4x1) + 16

                                                             = 32 g/mol

We know that 1 mole of any compound contains avagadro number ( 6.023x10²³) molecules

So 1 mole = 32 g of methanol contains 6.023x10²³ molecules

M g of methanol contains 9.06x10²⁴ molecules

M = ( 32x9.06x10²⁴ )/ (6.023x10²³ )

   = 481.3 g

Therefore the mass of methanol is 481.3 g