Recent questions and answers in Chemical reactions and thermochemistry

Calculate enthalpy change when $2.38\;g$ of carbon monoxide vapourises at its normal boiling point. $\Delta H_{vap}$ of $CO=6.04\;kj\;mol^{-1}$

answered Sep 17, 2018 by meena.p

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Most metals react with acids to form

answered Sep 17, 2018 by meena.p

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A system does 200 J of work and at the same time absorbs 150 J of heat. What is the internal energy change ?

answered Sep 17, 2018 by meena.p

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The equilibrium constant for the reaction is 10. Calculate the value of $\Delta G^{-}$ given

answered Sep 17, 2018 by meena.p

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Enthalpy of combustion of carbon to carbon dioxide is $-393.5\;kJ\;mol^{-1}$ . calculate the heat released upon formation of $35.2\;g$ of $CO_2$ from carbon to oxygen gas.

answered Sep 17, 2018 by meena.p

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A reaction , $A+B \to C+D+q$ is found to have an positive entropy change. The reaction will be

answered Sep 17, 2018 by meena.p

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The enthalpies of all elements in their standard states are :

answered Sep 17, 2018 by meena.p

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In a process , 701 J of heat is absorbed by a system and $394\;J$ of work is done by the system . What is the change in internal energy for the process ?

answered Sep 17, 2018 by meena.p

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How much heat is required to raise the temperature of an aluminium vessel weighting 1.25 kg from $25^{\circ}C$ to $55^{\circ}$ ? Molar heat capacity of Al is $24\;J\;mol^{-1}K^{-1}$

answered Sep 14, 2018 by meena.p

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When water is added to conc. $H_2SO_4$ it gets very hot. This happens because dilution of conc. $H_SO_4$ is ........

asked Sep 7, 2018 by meena.p

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The bond dissociation enthalpy of gaseous $H_2, Cl_2$ and $HCl$ are $435, 243$ and $431\; kJ mol^{-1},$ respectively. Calculate the enthalpy of formation of HCl gas.

answered Sep 7, 2018 by meena.p

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The enthalpies of combustion of carbon and carbon monoxide are $-393.5$ and $-283\;kJ\;mol^{-1}$ respectively . The enthalpy of formation of carbon monoxide per mole is

answered Sep 7, 2018 by meena.p

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The enthalpy change for a reaction does not depend upon

answered Sep 7, 2018 by meena.p

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For the reactions, $C+O_2 \to CO_2 ; \Delta H= -393\;J,2Zn +O_2 \to 2ZnO$ ; $\Delta H= -412\;J$

answered Sep 7, 2018 by meena.p

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If enthalpies of methane and ethane are respectively 320 and 360 calories then the bond energy of C−C bond is

answered Sep 4, 2018 by meena.p

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Energy required to dissociate 4 gm of gaseous hydrogen into free gaseous atoms is 208 kcal at $25^{\circ}C$ .The bond energy of H−H bond will be

answered Sep 4, 2018 by meena.p

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The enthalpy of an ideal gas depends only on the temperature.

answered Sep 4, 2018 by meena.p

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Heat transferred at constant pressure _____ the enthalpy of a system.

answered Sep 4, 2018 by meena.p

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Which reaction will result in a negative entropy?

answered Sep 4, 2018 by meena.p

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Change in enthalpy of a system is due to heat supplied at

answered Aug 26, 2018 by meena.p

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For an ideal gas, enthalpy becomes

answered Aug 26, 2018 by meena.p

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In a constant volume process, internal energy change is equal to

answered Aug 26, 2018 by meena.p

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Entropy is a

answered Aug 26, 2018 by meena.p

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A reaction will reach equilibrium when the system's entropy __________.

answered Aug 26, 2018 by meena.p

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$N_2(g) \qquad \Delta S_f=191.5\;J \\ O_2(g) \qquad \Delta S_f=205\;J \\ NO\qquad \Delta S_f=210.7\;J$ <br> What is the change in entropy for the following reaction? $N_{2(g)}+O_{2(g)}→2NO$

answered Aug 26, 2018 by meena.p

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Which of the following reactions represents a negative change in entropy?

answered Aug 26, 2018 by meena.p

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Which of the following does not represent an increase in entropy?

answered Aug 26, 2018 by meena.p

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The entropy of an isolated system always and becomes a at the state of equilibrium.

answered Aug 26, 2018 by meena.p

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Which of the following is true?

answered Aug 26, 2018 by meena.p

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The reaction $2KClO_{3(s)} \longrightarrow 2KCl_(s)+3O_{2(g)}$ is a(n)

answered Aug 23, 2018 by meena.p

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What happens when carbon dioxide is passed in lime water?

answered Aug 23, 2018 by meena.p

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Calculate the acid dissocation constant $K_a$ at $298\;K$ for a $0.010\;mol\;dm^{-3}$ solution of propanoic acid, $CH_3CH_2COOH$ The pH of this solution is $3.43$

answered Aug 23, 2018 by meena.p

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The correctly balanced equation for $FeS_2 +O_2 \to Fe_2O_3 +SO_2$ is ________

answered Aug 23, 2018 by meena.p

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Breaking of lead bromide into lead and bromine is an example of __________.

answered Aug 23, 2018 by meena.p

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Heat is evolved during:

answered Aug 23, 2018 by meena.p

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Oxidation is a process which involves:

answered Aug 23, 2018 by meena.p

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