There is no single chemical formula for ammonia and chlorine. When these two gases react with each other, they can form a variety of compounds, depending on the specific conditions of the reaction. Some possible compounds include:

* Ammonium chloride (NH4Cl): This is a white, crystalline solid that is highly soluble in water. It is formed when ammonia and hydrogen chloride gas are combined.

* Chloramine (NH2Cl): This is a colorless gas that is used as a disinfectant. It is formed when ammonia and chlorine gas are combined in the presence of a catalyst.

* Nitrogen trichloride (NCl3): This is a yellow-green liquid that is highly explosive. It is formed when ammonia and chlorine gas are combined at a high temperature.

* Tetrachloromethane (CCl4): This is a colorless liquid that is used as a solvent and as a cleaning agent. It is formed when methane gas is chlorinated in the presence of a catalyst.

The specific compound that is formed when ammonia and chlorine react depends on the ratio of the two gases, the temperature, and the presence of any catalysts.