Sodium reacts with oxygen to produce sodium oxide. 4Na(s) + O2(g) - - 2Na2O(s)
a. How many grams of Na20 are produced when 57.5 g of Na
reacts ?
b. If you have 18.0 g of Na, how many grams of O2 are
required for reaction?
c. How many grams of O2 are needed in a reaction that
produces 75.0 g of Na2O?

Explanation:

a )

4Na(s) + O₂(g) - - 2Na₂O(s)

4 x 23g    32g           2x62

92 g of Na produces 124 g of Na₂O(s)

57.5 g of Na produces (124 / 92) x 57.5

= 77.5 g of Na₂O(s)

b )

92 g of Na requires 32 g of O₂

18 g of Na requires ( 32 / 92 ) x 18

= 6.26 g of O₂

c )

128 g of Na₂O(s) requires 32 g of O₂

75 g of Na₂O(s) requires ( 32 / 128 ) x 75

= 18.75 g of O₂

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be