Question

how does the law of conservation of mass apply to this reaction: al + 3hcl → h₂ + alcl₃?
hydrogen and chlorine need to be balanced. there is an equal amount of aluminum on each side.
only the hydrogen needs to be balanced. there are equal numbers of aluminum and chlorine
the law of conservation of mass has already been applied. there is an equal number of each element on both sides of the equation.
the equation needs to be balanced. there are fewer hydrogen atoms in the equation than aluminum or chlorine.

Explanation:

Step1: Count atoms

• Reactants: \(1\) \(Al\), \(3\) \(H\), \(3\) \(Cl\)
• Products: \(1\) \(Al\), \(2\) \(H\), \(3\) \(Cl\)

Step2: Analyze balance

• \(Al\) is balanced (\(1\) on each side).
• \(H\) ( \(3\) vs \(2\)) and \(Cl\) ( \(3\) vs \(3\)): \(H\) and \(Cl\) need to be balanced.

Answer:

A. Hydrogen and chlorine need to be balanced. There is an equal amount of aluminum on each side.