Answer:
<em>4.72 × 10²⁴</em> molecules
Explanation:
<em>Number of mols of a substance = mass of substance/molar mass of substance</em>
Mass of carbon dioxide (CO2) = 345g
Molar Mass of Carbon = 12
Molar Mass of Oxygen = 16
Molar mass of CO2 = 12 + (16 x 2) = 44 g/mol
Number of mols of 345 grams of CO2 = 345/44 = 7.84 mols
<em>Number of molecules of a substance = number of mols x Avogadro's constant.</em>
<em> = 7.84 mol x 6.02 × 10²³ /mol</em>
<em> = 4.72 × 10²⁴</em>
<em>Hence, the number of molecules in 345 grams of carbon dioxide is 4.72 × 10²⁴ molecules.</em>