how much chlorine gas in grams is obtained from the decomposition of 10.0g NaCl
Whatever the reaction is, if all of the Cl in NaCl is convert4ed to Cl2, it will require two moles of NaCl to make one mole of Cl2. 10 gm of NaCl is 10/58.5 = 0.1709 moles
The number of moles of Cl2 formed will be 0.1709/2 = 0.0855
Each mole of Cl2 has a mass of 71 g.
Multiply the last two numbers for your answer.