instructions for #4-5, balance each equation after substituting symbols and formulas for words, remembering to include abbreviations for the physical state.
For subscripts, just make sure the number is in the right location in the compound formula.
4. Iodine crystals react with chlorine gas to form solid iodine trichloride.

5. Solid sodium bicarbonate reacts with hydrochloric acid [HCl (aq)] to produce aqueous sodium chloride, water, and carbon dioxide gas.