4. When the following equation is balanced, what is the coefficient for HCI?
|_Mg + HCI – MgCl2 + H2
A. $ B. 3 c. 1 D. 2 E. 4
I

Hey there!

Mg + HCl → MgCl₂ + H₂

Balance Cl.

1 on the left, 2 on the right. Add a coefficient of 2 in front of HCl.

Mg + 2HCl → MgCl₂ + H₂

Balance H.

2 on the left, 2 on the right. Already balanced.

Balance Mg.

1 on the left, 1 on the right. Already balanced.

Our final balanced equation: Mg + 2HCl → MgCl₂ + H₂

Hope this helps!