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Chemistry help??? Calculate the mass of magnesium formed upon passage of a current

0 votes

a) The half-reac2on for formation on of Mg upon electrolysis of molten MgCl2 is

Mg2+ +2e→Mg.

Calculate the mass of magnesium formed upon passage of a current of 60.0 A for a period of 4.00 × 103 s.

(b) How many seconds would be required to produce 50.0 g of Mg from MgCl2 if the current is 100.0 A? 

 

asked Apr 22, 2015 in CHEMISTRY by heather Apprentice
edited Apr 23, 2015 by bradely

2 Answers

0 votes

Step 1:

(a)

The current in the electrolysis of magnesium chloride is 60.0 A.

The time taken for the electrolysis of magnesium chloride is  Sec.

Half-reaction for formation of magnesium chloride : .

Charge of the magnesium ion is

image

Convert charge into Moles per electron :

Step 2:

Now convert amount of substance in moles.

Find out the Molecular weight.

image

image

image

Amount of magnesium is 302.23 g.

Solution:

Amount of magnesium is 302.23 g.

answered Apr 22, 2015 by Lucy Mentor
0 votes

Step 1:

(b)

The current in the electrolysis of magnesium chloride is 100.0 A.

The amount of the magnesium chloride is 50.0 g

Half-reaction for formation of magnesium chloride : .

Find out the amount of the magnesium chloride in moles.

image

Molecular weight of the magnesium chloride is 95.211 g/mol.

Step 2:

Total amount of magnesium chloride for 2 electrons.

Charge of the substance :

The current in the electrolysis of magnesium chloride:

image

The time taken for the electrolysis of magnesium chloride is  Sec.

Solution:

The time taken for the electrolysis of magnesium chloride is Sec.

answered Apr 22, 2015 by Lucy Mentor
edited Apr 22, 2015 by Lucy

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