Advertisements
Advertisements
प्रश्न
Heat of combustion is always ___________.
विकल्प
positive
negative
zero
either positive or negative
उत्तर
Heat of combustion is always negative.
APPEARS IN
संबंधित प्रश्न
Molar heat of vapourisation of a liquid is 4.8 kJ mol–1. If the entropy change is 16 J mol–1 K–1, the boiling point of the liquid is
Define molar heat capacity.
During complete combustion of one mole of butane, 2658 kJ of heat is released. The thermochemical reaction for above change is ______.
\[\ce{∆_f U^Θ}\] of formation of \[\ce{CH4 (g)}\] at certain temperature is – 393 kJ mol–1. The value of \[\ce{∆_f H^Θ}\] is ______.
On the basis of thermochemical equations (a), (b) and (c), find out which of the algebric relationships given in options (i) to (iv) is correct.
(a) \[\ce{C (graphite) + O2 (g) -> CO2 (g) ; ∆_rH = xkJ mol^{-1}}\]
(b) \[\ce{C (graphite) + 1/2 O2 (g) -> CO (g) ; ∆_rH = ykJ mol^{-1}}\]
(c) \[\ce{CO (g) + 1/2 O2 (g) -> CO2 (g) ; ∆_r H = zkJ mol^{-1}}\]
The standard molar entropy of \[\ce{H2O (l)}\] is 70 JK–1 mol–1. Will the standard molar entropy of \[\ce{H2O (s)}\] be more, or less than 70 JK–1 mol–1?
The molar enthalpy of vapourisation of acetone is less than that of water. Why?
Derive the relationship between ∆H and ∆U for an ideal gas. Explain each term involved in the equation.
The molar heat of formation of NH4NO3 (s) is −367.54 kJ and those of N2O (g), H2O (l) are 81.46 and −285.8 kJ respectively at 25°C and atmosphere pressure. The difference of ΔH and ΔE of the reaction \[\ce{NH4NO3(s) -> N2O (g) + 2H2O (l)}\] is ______ kJ.
A cylinder of gas supplied by Bharat Petroleum is assumed to contain 14 kg of butane. If a normal family requires 20,000 kJ of energy per day for cooking, butane gas in the cylinder last for ______ Days. (Δ Hc of C4 H10 = - 2658 JK per mole)
