Question

how much o2 is required to react with 1.8 grams of be to form 5.0 grams of beo?
reaction reactant(s) product(s)
be o2 beo
mass 1.8 g ? 5.0 g

Explanation:

Step1: 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.

Step2: Calculate mass of O2

Let the mass of O2 be $x$. We know that mass of Be + mass of O2=mass of BeO. So, $1.8 + x=5.0$.
Solve for $x$: $x = 5.0 - 1.8$.

Answer:

3.2 g