Question

The equation shows the reaction between magnesium and sulfuric acid.
[Ar: H, 1; O, 16; Mg, 24; S, 32]
Mg + H2SO4 → MgSO4 + H2
In this reaction, which mass of magnesium sulfate is formed when 6g of magnesium reacts with excess sulfuric acid?
An 8
B 24
C 30
D 60

Answer 1

(C) 30

As we know that,

No. of moles=

mol. wt.

wt.

Now,

Wt. of Mg=6g

Mol. wt. of Mg=24g

No. of moles of Mg in 6g=

24

6

=0.25 moles

Mg+H

2

SO

4

⟶MgSO

4

+H

2

from the above reaction,

1 mole of magnesium sulphate is formed when 1 mole of magnesium reacts.

Therefore,

0.25 mole of magnesium sulphate is formed when 0.25 mole of magnesium reacts.

Now,

Mol. wt. of MgSO

4

=120g

Therefore,

Wt. of 0.25 moles of MgSO

4

=0.25×120=30g

Hence 30g of magnesium sulphate is formd when 6g of magnesium reacts with excess of H

2

SO

4

hope it helps

Answer 2

Given - Mass of magnesium 6 gram

Find - Mass of magnesium sulfate formed

Solution - As the chemical reaction suggests, 1 mole of magnesium forms 1 mole of magnesium sulfate.

Now, calculating number of moles equivalent to 6 gram of magnesium.

Number of moles = mass/molecular mass

Number of moles = 6/24

Hence, number of moles = 1/4

Number of moles = 0.25

Thus, 1 mole of magnesium forms 1 mole of magnesium sulfate.

So, 0.25 mole of magnesium will form 0.25 mole of magnesium sulfate.

Further, converting moles of magnesium sulfate to mass.

Molecular mass of magnesium sulfate is 120 g/mol.

So, mass of magnesium sulfate = 0.25*120

Mass of magnesium sulfate = 30 grams.

Hence, C 30 grams of magnesium sulfate will form.