Chemistry questions
29404 published questions with worked solutions.
- The temperature of the system decreases in an __________
- A gas absorbs 250 J of heat and expands from 1 litre to 10 litre at constant external pressure of 0.5 atm. The values of q, W and...
- In a reaction, if U < 0, then heat _________
- If 2500 cal of heat is added to a system while the system does work equivalent to 3500 cal by expanding against the surrounding...
- The INCORRECT statement in relation to first law of thermodynamics i.e., U = q + W is, _________
- The spontaneous flow of heat is always _________
- For the two equations given below: (i) H_ 2(g) + 1 2 O_ 2(g) H_2O_ (l) + a_1 kJ (ii) H_ 2(g) + 1 2 O_ 2(g) H_2O_ (g) + a_2 kJ The...
- For the reaction, C_6H_ 12(l) + 9O_ 2(g) 6H_2O_ (l) + 6CO_ 2(g) ; H = -936.9 kcal, R = 0.002 kcal, T = 298 K, Which of the...
- For the gaseous reaction involving the complete combustion of isobutane, __________
- Point out the WRONG statement from the following, in relation to enthalpy
- A mixture of two moles of carbon monoxide and one mole of oxygen, in a closed vessel is ignited to convert the carbon monoxide to...
- For CaCO_ 3(s) CaO_ (s) + CO_ 2(g) at 977 °C; H = 176 kJ/mol, then U is _________
- The enthalpy change when 1 g of water is frozen at 0 °C ( _ fus H^ = 1.435 kcal/mol) is _______
- 50 mL of water takes 5 minutes to evaporate from a vessel on a heater connected to an electric source which delivers 400 W. The...
- In which of the following thermochemical changes H^ is always negative?
- The mathematical expression for the standard enthalpy of sublimation is given by _________ (Here, _ sub H^ = _ sublimation H^ , _...
- If the heat of combustion of solid benzoic acid at constant volume is -321.30 kJ at 27 °C, the heat of combustion at constant...
- Values of heats of formation for SiO_2 and MgO are -48.4 and -34.7 kJ respectively. The heat of the reaction 2Mg_ (s) + SiO_ 2(s)...
- The enthalpy of formation of ammonia is -46.0 kJ ,mol^ -1 . The enthalpy for the reaction 2N_ 2(g) + 6H_ 2(g) 4NH_ 3(g) ; is...
- The standard molar heat of formation of ethane, CO_2 and H_2O_ (l) are respectively -21.1, -94.1, and -68.3 kcal. The standard...