Answer:
The correct answer is - 3.012×10^23 molecules
Explanation:
The number of molecules is present in any mole of an element or compound are the same. To find the molecules you need to multiply the number of the moles of the compound by Avogadro's number:
Moles are calculated from the molecular weight, for AlF3
= 26.98 + 3×19
= 26.98 + 57
= 83.98
Then moles in 42 grams:
= 42/83.98
= 0.5001190 moles
Now the number of molecules = moles*Avogadro's number
= 0.500110×6.022×10^23
= 3.011×10^23 molecules
You can search that up online it’s not that hard but good luck !!
1 molecule CO2 has 2 atoms O.
1 mole CO2 has 2 moles O,
1.5 mole CO2 has 2*1.5 mole O=3.0 mole O