Description : Given standard enthalpy of formation of `CO(-110 "KJ mol"^(-1))` and `CO_(2)(-394 "KJ mol"^(-1))`. The heat of combustion when one mole of graphite bu
Last Answer : Given standard enthalpy of formation of `CO(-110 "KJ mol"^(-1))` and `CO_(2)(-394 "KJ mol"^(-1))`. The heat ... B. `-284` KJ C. `-394` KJ D. `-504` KJ
Description : Standard enthalpy of formation of ethane is -84.7kjper mol calculate the enthalpy change for the formation of 0.1kg ethane
Last Answer : Standard enthalpy of formation of ethane is -84.7kjper mol calculate the enthalpy change for the formation of 0.1kg ethane
Description : Write an expression in the form of chemical equation for the standard enthalpy of formation (∆Hf) of CO (g).
Last Answer : Ans. C(s) +1/2 O2(g) → CO (g)
Description : Assertion: The enthalpy of formation of gaseous oxygen molecules at `298K` and under1 atm is zero. Reason: The entropy of formation of gaseous oxygen
Last Answer : Assertion: The enthalpy of formation of gaseous oxygen molecules at `298K` and under1 atm is zero. ... D. If both Assertion & Reason are false.
Description : Since the enthalpy of elements in their natural state is taken to be zero, the heat of formation `(Delta_(f)H)` of compounds
Last Answer : Since the enthalpy of elements in their natural state is taken to be zero, the heat of formation `( ... C. is zero D. May be positive or negative
Description : Out of carbon(diamond)and carbon (graphite) whose enthalpy of formation is taken as zero?
Last Answer : Ans. Enthalpy of formation of carbon in the form of graphite is taken as zero because it is a more commonly found in stable form of carbon.
Description : Pick out the correct statement. (A) Like internal energy and enthalpy, the absolute value of standard entropy for elementary substances is zero (B) Melting of ice involves increase in enthalpy and ... of an ideal gas depends only on its pressure (D) Maximum work is done under reversible conditions
Last Answer : (D) Maximum work is done under reversible conditions
Description : The enthalpy of formation of ammonia is `-46.0 KJ mol^(-1)` . The enthalpy change for the reaction `2NH_(3)(g)rarr N_(2)(g)+3H_(2)(g)` is :
Last Answer : The enthalpy of formation of ammonia is `-46.0 KJ mol^(-1)` . The enthalpy change for the reaction `2NH_(3)(g) ... mol^(-1)` D. `-92.0 KJ mol^(-1)`
Description : The enthalpy changes of formation of the gaseous oxides of nitrogen `(N_(2)O` and `NO)` are positive because of `:`
Last Answer : The enthalpy changes of formation of the gaseous oxides of nitrogen `(N_(2)O` and `NO)` are positive ... The tendency of oxygen to form `O^(2-)`
Description : The enthalpy of formation of `CO(g), CO_(2)(g),N_(2)O(g)` and `N_(2)O_(4)(g)` is `-110,-393,+81` and 10 kJ / mol respectively. For the reaction `N_(2)
Last Answer : The enthalpy of formation of `CO(g), CO_(2)(g),N_(2)O(g)` and `N_(2)O_(4)(g)` is `-110,-393,+81` and 10 ... is A. `-212` B. `+212` C. `+778` D. `-778`
Description : Bond dissociation enthalpy of `H_(2)` , `Cl_(2)` and `HCl` are `434, 242` and `431KJmol^(-1)` respectively. Enthalpy of formation of `HCl` is
Last Answer : Bond dissociation enthalpy of `H_(2)` , `Cl_(2)` and `HCl` are `434, 242` and `431KJmol^(-1)` respectively. ... kJ mol^(-1)` D. `-245 kJ mol^(-1)`
Description : Which reaction shows that the enthalpy of formation of H2S is Hf -20.6 kJmol?
Last Answer : H2(g) + S(s) —> H2S + 20.6 kJ
Description : What is the sign of enthalpy of formation of highly stable compound?
Last Answer : Ans. Negative.
Description : Entropy change of the reaction, H2O (liquid) → H2O (gas), is termed as the enthalpy of (A) Solution (B) Vaporisation (C) Formation (D) Sublimation
Last Answer : (B) Vaporisation
Description : The enthalpy change when ammonia gas is dissolved in water is called the heat of (A) Solution (B) Formation (C) Dilution (D) Combustion
Last Answer : (A) Solution
Description : What is the standard enthalpy change at 298 K for the following reaction? `CO_(2) (g)+ C("diamond") rarr 2CO(g)` Given : `DeltaH_(f)^(@)(CO,g) = - 110
Last Answer : What is the standard enthalpy change at 298 K for the following reaction? `CO_(2) (g)+ C("diamond") rarr 2CO(g ... `+172.5 kJ//mol` D. `170.5 kJ//mol`
Description : `Delta_(f)^(@)` for `CO_(2(g)), CO_((g))` and `H_(2)O_((g))` are `-393.5,-110.5` and `-241.8kJ mol^(-1)` respectively. The standard enthalpy change `(
Last Answer : `Delta_(f)^(@)` for `CO_(2(g)), CO_((g))` and `H_(2)O_((g))` are `-393.5,-110.5` and `-241.8kJ mol^(-1 ... A. `524.1` B. `41.2` C. `-262.5` D. `-41.2`
Description : Given that standard heat enthalpy of `CH_(4), C_(2)H_(4)` and `C_(3)H_(8)` are -17.9, 12.5, -24.8 Kcal/mol. The `Delta H` for `CH_(4)+C_(2)Hrarr C_(3)
Last Answer : Given that standard heat enthalpy of `CH_(4), C_(2)H_(4)` and `C_(3)H_(8)` are -17.9, 12.5, -24.8 Kcal ... . `-30.2` Kcal C. 55.2 Kcal D. `-19.4` Kcal
Description : Give enthalpy (H) of all elements in their standard state.
Last Answer : Ans. In standard state enthalpies of all elements is zero.
Description : The enthalpy of a reaction at 273 K. is -3.57 KJ. What will be the enthalpy of reaction at 373 K if `DeltaC_(p)` = zero :-
Last Answer : The enthalpy of a reaction at 273 K. is -3.57 KJ. What will be the enthalpy of reaction at 373 K if `DeltaC_ ... C. `-3.57xx(373)/(273)` D. `-375`
Description : From the elements: Cl, Br, F, O, Al, C, Li, Cs and Xe; choose the following: (a) The element with highest negative electron gain enthalpy. (b) The element with lowest ionization enthalpy. ( ... . (f)The element which belongs to zero group. (g) The elements which forms largest number of compounds.
Last Answer : Ans. (a). The element chlorine (Cl) has the highest negative electron gain enthalpy. (b). The element cesium (Cs) has lowest ionization enthalpy. (c). The element fluorine F has lowest atomic radius. (d ... zero group (or group 18). (g). The element carbon (C) forms the largest number of compounds.
Description : If an ideal solution is formed by mixing two pure liquids in any proportion, then the __________ of mixing is zero (A) Enthalpy (B) Volume (C) Both 'a' & 'b' (D) Neither 'a' nor 'b'
Last Answer : (C) Both 'a' & 'b'
Description : Pick out the wrong statement. (A) Minimum number of degree of freedom of a system is zero (B) Degree of freedom of a system containing a gaseous mixture of helium, carbon ... ) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation
Last Answer : (D) Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation
Description : In the reaction, C + O2 → CO2; ΔH = - 94 kcal. What is the heat content (enthalpy) of O2? (A) -94 kcal (B) > -94 kcal (C) < - 94 kcal (D) Zero
Last Answer : (D) Zero
Description : For an exothermic reaction (A) Only enthalpy change (ΔH) is negative (B) Only internal energy change (ΔE) is negative (C) Both ΔH and ΔE are negative (D) Enthalpy change is zero
Last Answer : (C) Both ΔH and ΔE are negative
Description : Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is (A) Positive (B) Negative (C) Zero (D) Infinity
Last Answer : C) Zero
Description : Enthalpy changes over a constant pressure path are always zero for __________ gas. (A) Any (B) A perfect (C) An easily liquefiable (D) A real
Last Answer : (B) A perfect
Description : An ideal gas is compresses isothermally. The enthalpy change is a. Always negative b. Always positive c. zero d. undefined
Last Answer : zero
Description : What happens to the internal energy of water at reference temperature where enthalpy is zero? a. Becomes negative b. Becomes positive c. Remains constant d. Cannot be defined
Last Answer : Becomes negative
Description : Which of the following equations respresents standard heat of formation of `CH_(4)` ?
Last Answer : Which of the following equations respresents standard heat of formation of `CH_(4)` ? A. `C_(("diamond"))+2H_ ... "graphite"))+4H_((g))rarr CH_(4(g))`
Description : Define standard feat of formation
Last Answer : The amount of heat liberated of absorbed when one mole of compound is formed in its standard state from its elements in their standard state is called standard heat of formation ( Hf *)
Description : Heat of formation of an element in its standard state is (A) 0 (B) < 0 (C) > 0 (D) A function of pressure
Last Answer : (A) 0
Description : In case of physical adsorption, the difference between heat of adsorption and heat of normal condensation is (A) Equal to the heat of formation of surface compound (B) Equal to the heat of wetting (C) Zero (D) Called integral heat of adsorption
Last Answer : (B) Equal to the heat of wetting
Description : Pick out the correct statement. (A) If an insoluble gas is passed through a volatile liquid placed in a perfectly insulated container, the temperature of the liquid will increase (B) A ... compound is defined as the heat of reaction leading to the formation of the compound from its reactants
Last Answer : (D) The heat of formation of a compound is defined as the heat of reaction leading to the formation of the compound from its reactants
Description : The catch water drains are provided in the a) Formation in the embankment b) Formation in cutting* c) Zero fills formation d) Steep gradient
Last Answer : b) Formation in cutting*
Description : Which of the following state function is not zero at standard state :-
Last Answer : Which of the following state function is not zero at standard state :- A. Enthalpy B. Entropy C. Free energy D. None
Description : Does the Zero Halliburton Slimline Aluminum Briefcase protect your valuables better than a standard leather breifcase?
Last Answer : The Halliburton briefcase is made of aluminum, but has roughly the same durablility as their leather briefcases.
Description : The free energy change, AG (A) Is directly proportional to the standard free energy change, AG (B) Is equal to zero at equilibrium (C) Can only be calculated when the reactants and products are present at 1mol/1 concentrations (D) Is equal to –RT in keq
Last Answer : B
Description : Pick out the wrong statement. (A) Enthalpies of all elements in their standard states are assumed to be zero (B) Combustion reactions are never endothermic in nature (C) Heat of reaction ... to the change in internal energy (D) Clausius-Clapeyron equation is not applicable to melting process
Last Answer : (D) Clausius-Clapeyron equation is not applicable to melting process
Description : Which of the following is standard temperature and pressure (STP)? A. 0 degree Celsius and one atmosphere B. 32 degree Fahrenheit and zero pressure C. 0 degree Kelvin and one atmosphere D. 0 degree Fahrenheit and zero pressure
Last Answer : 0 degree Celsius and one atmosphere
Description : The Manufacturer of aeration devices reports the oxygen transfer rate of the device obtained through laboratory tests carried under standard conditions. Such standard condition are : (a) Wastewater at zero DO, 25°C and 760 mm ... DO, 20°C and 760 mm Hg (d) Wastewater at zero DO, 0°C and 700 mm Hg
Last Answer : (c) Tapwater at zero DO, 20°C and 760 mm Hg