Question

How many grams of sodium oxide can be synthesized from 17.4 g of sodium? Assume that more than enough oxygen is present. The balanced equation is:

4Na(s) + O2(g) → 2Na2O(s)

Answer 1

Molar mass of Na = 22.99 g/mol

mass(Na)= 17.4 g

we have below equation to be used:

number of mol of Na,

n = mass of Na/molar mass of Na

=(17.4 g)/(22.99 g/mol)

= 0.7569 mol

we have the Balanced chemical equation as:

4 Na + O2 ---> 2 Na2O

Molar mass of Na2O,

MM = 2*MM(Na) + 1*MM(O)

= 2*22.99 + 1*16.0

= 61.98 g/mol

From balanced chemical reaction, we see that

when 4 mol of Na reacts, 2 mol of Na2O is formed

mol of Na2O formed = (2/4)* moles of Na

= (2/4)*0.7569

= 0.3784 mol

we have below equation to be used:

mass of Na2O = number of mol * molar mass

= 0.3784*61.98

= 23.5 g

Answer: 23.5 g