Question

1. answer the following questions based on the balanced equation provided below for the reaction that occurs when zinc metal is added to hydrochloric acid.

if 12 g of mg(s) was used in the reaction with 8 g of o₂(g). how much mgo was created? this question requires you to apply the conservation of mass to solve for the missing mass. (2 marks)
2mg(s) + o₂(g) → 2mgo(s)

Explanation:

Step1: Identify reactant masses

The mass of magnesium ($Mg$) is $m_{Mg}=12\ g$ and the mass of oxygen ($O_2$) is $m_{O_2} = 8\ g$.

Step2: Apply law of conservation of mass

According to the law of conservation of mass, the total mass of reactants equals the total mass of products in a chemical - reaction. The reactants are $Mg$ and $O_2$, and the product is $MgO$. So the mass of $MgO$ created, $m_{MgO}$, is the sum of the masses of $Mg$ and $O_2$.
$m_{MgO}=m_{Mg}+m_{O_2}$
$m_{MgO}=12\ g + 8\ g$
$m_{MgO}=20\ g$

Answer:

$20\ g$