Municipal waste (25.0 kg) contains 40.0% PVC, (C2H3Cl)_n, by mass. On incineration all chlorine leaves as HCl: 2C2H3Cl + 5O2 -> 4CO2 + 2H2O + 2HCl. Use C 12, H 1, Cl 35.5. The mass of HCl formed is

JEE Advanced levelSingle correct optionDifficulty 3 of 3ev213

Municipal waste (25.0 kg) contains 40.0% PVC, $(C X_{2} H X_{3} Cl) X_{n}$ , by mass. On incineration all chlorine leaves as HCl: $2 C X_{2} H X_{3} Cl + 5 O X_{2} 4 CO X_{2} + 2 H X_{2} O + 2 HCl$ . Use C 12, H 1, Cl 35.5. The mass of HCl formed is

PVC mass

= 25.0 \times 0.400 = 10.0

kg; the repeat unit

C X_{2} H X_{3} Cl

has mass 62.5. One HCl (36.5) forms per unit, so HCl

= 10.0 \times 36.5/62.5 = 5.84

kg. Using the whole waste gives 14.6 kg and ignoring the 1:1 ratio gives other wrong values.