Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_73 (prefix VARCHAR, chemical_class VARCHAR)
### Question:
What prefix has chemical class Iodoalkane?
### Answer:
SELECT prefix FROM table_name_73 WHERE chemical_class = "iodoalkane"