A 20.0 mL solution containing 0.2 g impure H₂O₂ reacts completely with 0.316 g of KMnO₄ in acid solution. The purity of H₂O₂ (in %) is _____________
(mol. wt. of H₂O₂ = 34; mol. wt. of KMnO₄ = 158)

For one mole of an ideal gas, which of these statements must be true?
(a) U and H each depends only on temperature
(b) Compressibility factor z is not equal to 1
(c) C_{P, m} – C_{V, m} = R
(d) dU = C_VdT for any process

Which of the following will react with CHCl₃ + alc. KOH?

If the system of equations
x - 2y + 3z = 9
2x + y + z = b
x - 7y + az = 24,
has infinitely many solutions, then a - b is equal to.........