Volume of gas calculation (1 Viewer)

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Hi, if anyone could explain how to do the question below it would be greatly appreciated!

1g of magnesium is dissovled in excess of HCL, what volume of hydrogen ( measured at zero degrees and 1.00 atomspheres) is formed?
The answer is 0.92L

thanks!!!

 

[Dreamerish*~]

The equation of the reaction is:

Mg + 2HCl → MgCl₂ + H₂

We have 1 g of Mg reacting with excess HCl.

n = m/M

= 1/24.3

= 0.04115

The molar ratio of Mg to H₂ is 1:1. Therefore with every mole of Mg, one mole of H₂ is produced. This means for 0.04115 moles of Mg, 0.04115 moles of H₂ is produced.

At 0°C and 1 atm, one mole of any gas occupies 22.41 L.

. : 0.04115 x 22.41 = 0.92 L (2 d.p.)

This is because for every one mole of any gas, the volume occupied is 22.41. Since we have 0.04115 moles, then the volume would be 0.04115 x 22.41.