Photolithography is the process by which we make the tiny circuits necessary for the tiny transistors in today’s electronics. To do this we must create very thin films of a chemical burn carveout channels that are filled with metal to creat the circuits. One posible candidate for making these thin films is butyltin trichloride, C4H9SnCl3. In the presence water this chemical loosens some of its bound chloride atoms producing hydrochloric acid HCI, arrording to the chemical equation below C4H9SnCl3+H2O=C4H9Sn(OH)2Cl+HCl