Balanced equation: 4HCl + O₂ → 2Cl₂ + 2H₂O
mole ratio of HCl : O₂ is 4 : 1
∴ if moles of HCl = 2.3 mol
then mol of O₂ = 2.3 mol ÷ 4
= 0.575 mol
mass of O₂ = moles of O₂ × molar mass of O₂
= 0.575 mol × (16 × 2) g/mol
= 18.4 g
The correct answers are:
1. B. Mg loses two electrons.
When Mg and Br combine, 2 atoms of Br attaches itself to
Mg. The chemical reaction is:
Mg + Br ---> MgBr2
Since Br is more electronegative than Mg, then Mg loses
an electron per Br therefore losing 2 electrons.
2. D. An atom that gains electrons must be attracted to an atom
that loses electrons.
An ionic bond is formed when one molecule is more
electronegative than the other molecule which results in gaining and losing of
electrons. The more electronegative molecule gains electron while the less
electronegative loses electron.
