Chemistry questions
29404 published questions with worked solutions.
- In a calorimeter, the temperature of the calorimeter increases by 6.12 K, the heat capacity of the system is 1.23 kJ/g/deg. What...
- Heat of formation of H_2O is -188 kJ/mol and H_2O_2 is -286 kJ/mol. The enthalpy change for the reaction, 2H_2O_2 2H_2O + O_2
- 2.1 g of Fe combines with S evolving 3.77 kJ. The heat of formation of FeS (in kJ/mol) is
- The standard enthalpy of formation of NH_3 is -46.0 kJ mol^ -1 . If the enthalpy of formation of H_2 from its atoms is -436 kJ...
- Calculate the bond enthalpy of Xe - F bond as given in the equation, XeF_4(g) Xe^ + (g) + F^ - (g) + F_2(g) + F(g) ; _rH = 292...
- Which of the following statement is incorrect about the equation? C_2H_5OH(l) + 3O_2(g) 2CO_2(g) + 3H_2O(l) , _rH^ = -1367 kJ...
- Calculate the enthalpy of vaporisation of I_2 if the sublimation energy and enthalpy of fusion of I_2 is 57.3 kJ mol^ -1 and 15.5...
- For the reactions A B , H = +24 kJ/mol and B C ; H = -18 kJ/mol, the decreasing order of enthalpy of A, B, C follows the order
- The ratio of enthalpy of vaporisation and the normal boiling point of a liquid approximately equals to ...(i)... . The above...
- The reaction of cyanamide, NH_4CN(s) , with dioxygen was carried out in a bomb calorimeter, and U was found to be -742.7 kJ mol^...
- Consider the following reactions, (i) 12 N_2(g) + 12 O_2(g) NO(g); _rH^ = 90 kJ ,mol^ -1 (ii) NO(g) + 12 O_2(g) NO_2(g); _rH^ =...
- _f U^ for the formation of CH_4(g) at certain temperature is -393 kJ mol^ -1 . The value of _f H^ is
- An ideal gas is allowed to expand against a constant pressure of 2 bar from 10 L to 50 L in one step. The amount of work done by...
- What would be the heat released when an aqueous solution containing 0.5 mole of HNO_3 is mixed with 0.3 mole of OH^- ? (Enthalpy...
- The standard molar heat of formation of ethane, CO_2 and water (l) are respectively -21.1, -94.1 and -68.3 kcal . The standard...
- The H_f^ of O_3 , CO_2 , NH_3 and HI are 142.2, -393.3, -46.2 and +25.9 kJ per mol, respectively. The order of their increasing...
- One mole of methanol when burnt in O_2 , gives out 723 kJ ,mol^ -1 of heat. If one mole of O_2 is used, what will be the amount...
- H_f^ (298 K) of methanol is given by the chemical equation,
- Formation of a solution from two components can be considered as (1) pure solvent separated solvent molecules, H_1 (2) pure...
- If the value of C_p for nitrogen gas is 7 J ,K^ -1 ,mol^ -1 , then the value of H on heating 28 g of nitrogen gas from 0^ to 100^...