Word equation: Magnesium chloride + Water → Magnesium hydroxide + Hydrochloric acid
Type of Chemical Reaction: For this reaction we have a neutralization reaction.
Balancing Strategies: This is a neutralization reaction, and can also called a double displacement reaction. It's neutralization because we have a base, the magnesium hydroxide, added to an acid, HCl. The products are a salt (MgCl2) and and water.
We can say it's double displacement because the Mg and the H essentially switch places.
To balance a reaction I recommend changing the coefficient in front of the H2O to get an even number of oxygen atoms. That should get you started.