Question

The phosphorus atom in PCl3 would be expected to have a ? A) 3+ charge. B) partial negative (δ-) charge. C) 3- charge. D) partial positive (δ+) charge.

Answer 1

The answer is D) partial positive (`delta^+`) charge.

The phosphorus atom in the covalent compound phosphorus trichloride, `"PCl"_3`, has an electronegativity of 2.19, and the chlorine atoms each have an electronegativity of 3.16, therefore the difference in electronegativity is 0.97, indicating a polar covalent bond between the phosphorus atom and each of the three chlorine atoms. The more electronegative chlorine atoms will attract the shared electrons toward themselves, creating a partial negative (`delta^-`) charge on the chlorine atoms. This will cause the phosphorus atom to develop a partial positive (`delta^+`) charge.