Answer:
119.28g
Explanation:
Data obtained from the question include:
Number of mole of Si = 4.26 mol
Molar Mass of Si = 28g/mol
Mass of Si =?
Number of mole = Mass /Molar Mass
Mass = number of mole x molar Mass
Mass of Si = 4.26 x 28
Mass of Si = 119.28g
Molecular formula of sulfur trioxide is SO₃
Molar mass of SO₃ is - 32 + (16 x 3 ) = 80 g/mol
1 mol of any substance consists of 6.022 x 10²³ units. In 1 mol of SO₃ there are 6.022 x 10²³ molecules of SO₃
in 80 g of SO₃ - there are 6.022 x 10²³ molecules of SO₃
Therefore in 78 g of SO₃ - there are 6.022 x 10²³ /80 x 78 = 5.871 x 10²³ SO₃ molecules