0 . 75 moleof solid 'A_(4)'and 2 moles of gaseous O_(2) are heated in a sealedvessel, completely using up thereactants and producing only one compound. It is found that when the temperature is reduced to the initial temperature, the contents of the vessel exhibita pressure equal to halfthe original pressure. Whatconclusions can be drawn from these data aboutthe product of the reaction ?

0 . 75 moleof solid 'A_(4)'and 2 moles of gaseous O_(2) are heated in

1.	0 . 75 moleof solid 'A_(4)'and 2 moles of gaseous O_(2) are heated in a sealedvessel, completely using up thereactants and producing only one compound. It is found that when the temperature is reduced to the initial temperature, the contents of the vessel exhibita pressure equal to halfthe original pressure. Whatconclusions can be drawn from these data aboutthe product of the reaction ?
Answer» SOLUTION :Asboth the reactants are limiting reagents, the ratio of stoichiometriccoefficientsof the reactantswould be 0 . 75 : 2 or 3 : 8 for `A_(4) and O_(2)` . Thus, `3 A_(4) + 8 O_(2) to` Product As the product EXERTS considerable pressure, it has to be a gas. Further, as the final pressure is HALF thatof oxygen initially PRESENT, the stoichiometriccoefficient of the product must be halfthatof `O_(2)`, i.e., 4. Obviously, the molecularformula would be `A_(3) O_(4)` to balance theequation. `3 A_(4) + 8 O_(2) to 4 A_(3) O_(4)`