Question

3.0 g of magnesium was added to 12.0 g of ethanoic acid.
Mg + 2CH3COOH → (CH3COO)2Mg + H2
The mass of one mole of Mg is 24 g. The mass of one mole of CH3COOH is 60 g.
Which one, magnesium or ethanoic acid, is in excess? You must show your reasoning

Answer 1

Answer:

magnesium

Explanation:

24g of Mg reacts with 120g of ethanoic acid  (2moles)

3g of Mg reacts will react with= 120/24 x3g ethanoic acid

                                                 =>15g of ethanoic acid

but only 12g of ethanoic acid is present therefore magnesium is in excess

Answer 2

Answer:

magnesium

Explanation:

Mg + 2CH3COOH ---> (CH3COO)2Mg + H2

1 mole Mg requires 2 moles of CH3COOH

hence, 24g (1 mole) of Mg will need 120g (2 moles) of CH3COOH

and 3g of Mg will need 15g of CH3COOH

But we have only 12g CH3COOH

so, Mg is in excess