Question

1) How many grams of CO are needed to react with an excess of Fe2O3 to produce 225.5 gFe? Numbers after symbols are subscripts unless there is a ^ to show it is an exponent. ........... Fe2O3(s) +3CO(g) -- > 3 CO2(g) + 2 Fe(s) ...........

2) Solid sodium reacts violently with water producing heat, hydrogen gas and sodium hydroxide. How many molecules of hydrogen gas are produced when 65.4 g of sodium are added to water? Numbers after symbols are subscripts unless there is a ^ to show it is an exponent. ............ 2 Na(s) +2 H2O(l) -- > 2 NaOH(aq) + H2(g) ...........

Answer 1

1)
Moles = mass / Mr
Mr of Fe = 56
Moles of Fe = 225.5 / 56
Moles of Fe = 4.03

Molar ratio CO : Fe = 3 : 2
Moles of CO = 4.03 x 3/2
Moles of CO = 6.04 moles

Mass of CO = 6.04 x (12 + 16)
Mass of CO = 169.1 grams


2)
Moles of Na = 65.4 / 23
Moles of Na = 2.84

Molar ratio Na : H₂ = 2 : 1
Moles of H₂ = 1.42
Each mole has 6.02 x 10²³ particles

Molecules of Hydrogen = 1.42 x 6.02 x 10²³
Molecules of Hydrogen = 8.55 x 10²³ particles