Question

When magnesium chloride reacts with water, 5.85 L HCl(g) is produced.

molar mass of HCl = 36.5 g/mol
molar mass of MgCl2 = 95.2 g/mol

How many moles of HCl was produced?
How many moles of MgCl2 reacted?
What mass of MgCl2 reacted?

Answer 1

Answer: (i) 0.261 moles of HCl, (ii) 0.131 moles of
`MgCl_2` and (iii) 12.5 grams of
`MgCl_2`

Step-by-step explanation: The balanced equation for the formation of HCl by the reaction magnesium chloride with water is:

`MgCl_2+2H_2O\rightarrow 2HCl+Mg(OH)_2`

From above balanced equation, there is 1:2 mol ratio between magnesium chloride and HCl.

As per the given information, 5.85 L of HCl gas is produced. here, temperature and pressure is not mentioned, so let's assume STP conditions.

At STP, volume of 1 mol of a gas is 22.4 L. With the help of this, we can calculate the moles of HCl present in 5.85 L.

`5.85LHCl((1mol)/(22.4L))`

= 0.261 mol HCl

As there is 1:2 mol ratio between magnesium chloride and HCl, we can calculate the moles of magnesium chloride from the above calculated moles of HCl as:

`0.261molHCl((1molMgCl_2)/(2molHCl))`

= 0.131 mol
`MgCl_2`

Molar mass of magnesium chloride is given as 95.2 gram per mol. On multiplying the moles by molar mass we can calculate its mass reacted.

`0.131molMgCl_2((95.2g)/(1mol))`

= 12.5 g
`MgCl_2`

Answer 2

Answer: How many moles of HCl was produced?

⇒ 0.261 moles of HCl

How many moles of MgCl2 reacted?

⇒ 0.131 moles of MgCl2

What mass of MgCl2 reacted?

⇒ 12.4 g MgCl2

Step-by-step explanation:

i just did it