To determine the polarity of a molecule, you need to consider the electronegativity difference between the atoms and the molecular geometry.
1. H2 (hydrogen gas): Hydrogen gas is composed of two hydrogen atoms bonded together. Since hydrogen and hydrogen have similar electronegativities, the electronegativity difference is negligible. Therefore, H2 is a nonpolar molecule.
2. HBr (hydrogen bromide): Hydrogen bromide consists of a hydrogen atom bonded to a bromine atom. Bromine is more electronegative than hydrogen, creating an electronegativity difference. Additionally, the molecule has a linear geometry. Due to the polarity of the H-Br bond and the overall molecular shape, HBr is a polar molecule.
3. BrCl (bromine chloride): Bromine chloride is composed of a bromine atom bonded to a chlorine atom. Both bromine and chlorine are highly electronegative, resulting in a significant electronegativity difference. The molecule has a bent or V-shaped geometry. Considering the polarity of the Br-Cl bond and the molecular shape, BrCl is a polar molecule.
4. NH3 (ammonia): Ammonia consists of a nitrogen atom bonded to three hydrogen atoms. Nitrogen is more electronegative than hydrogen, causing an electronegativity difference. The molecule has a pyramidal or trigonal pyramidal geometry. As a result of the N-H bonds' polarity and the molecular shape, NH3 is a polar molecule.
5. CCl4 (carbon tetrachloride): Carbon tetrachloride consists of a carbon atom bonded to four chlorine atoms. Although chlorine is more electronegative than carbon, the molecule has a tetrahedral geometry, which leads to a symmetrical distribution of charge. Due to the canceling out of polarities caused by the molecular shape, CCl4 is a nonpolar molecule.
By considering the electronegativity difference and the molecular geometry of each molecule, you can determine whether they are polar or nonpolar.
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