Question

plz help me to solve this question

Answer 1

• Molecular mass  

C(12*12 )+ H(1*22) + O(16*11) = 342g molecular mass

• Number of atoms in 1 molecule of sucrose  

12+22+11 = 45 number of atoms

• Number of gram molecules in 34.2g of sucrose

1 mole contain of 6.02x1023 molecules

For 34.2g :

6.02x10^23* 34.2/342 = 6.02x10^22 molecules

Answer 2

The formula of sucrose is C₁₂H₂₂O₁₁

i) The molecular mass of sucrose = 12x12 + 22x1 + 11x16

= 342 grams.

ii) since one molecule contains 12 atoms of carbon, 22 atoms of hydrogen and 11 atoms of oxygen,

hence total number of atoms in one molecule of sucrose,

= 12 + 22 + 11

= 45 atoms

iii) since the molecular weight of sucrose is 342 grams

=> 342 grams contains = 6.022 x 10²³ molecules

=> 34.2 grams contains = 6.022 x 10²³/10

= 6.022 x 10²² molecules.

Hence 34.2 g of sucrose contains 6.022 x 10²² molecules.