Recent questions tagged chemical-reactions-and-thermochemistry

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

asked Sep 17, 2018 by meena.p

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Most metals react with acids to form

asked 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 ?

asked 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

asked 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.

asked 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

asked Sep 17, 2018 by meena.p

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The enthalpies of all elements in their standard states are :

asked 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 ?

asked Sep 17, 2018 by meena.p

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Calculate the entropy change when $36\;g$ of liquid water evaporates at $373\;K(\Delta _{vap} H=40.63\;kJ\;mol^{-1})$

asked Sep 14, 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 $24\;J\;mol^{-1}K^{-1}$

asked 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.

asked 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

asked Sep 7, 2018 by meena.p

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The enthalpy change for a reaction does not depend upon

asked Sep 7, 2018 by meena.p

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

asked 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

asked 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

asked Sep 4, 2018 by meena.p

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

asked Sep 4, 2018 by meena.p

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

asked Sep 4, 2018 by meena.p

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Which reaction will result in a negative entropy?

asked Sep 4, 2018 by meena.p

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

asked Aug 26, 2018 by meena.p

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For an ideal gas, enthalpy becomes

asked Aug 26, 2018 by meena.p

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

asked Aug 26, 2018 by meena.p

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Entropy is a

asked Aug 26, 2018 by meena.p

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

asked 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? $N_{2(g)}+O_{2(g)}→2NO$

asked Aug 26, 2018 by meena.p

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

asked Aug 26, 2018 by meena.p

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

asked 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.

asked Aug 26, 2018 by meena.p

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Which of the following is true?

asked Aug 26, 2018 by meena.p

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

asked Aug 23, 2018 by meena.p

1 answer

What happens when carbon dioxide is passed in lime water?

asked 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 $3.43$

asked Aug 23, 2018 by meena.p

1 answer

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

asked Aug 23, 2018 by meena.p

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

asked Aug 23, 2018 by meena.p

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Heat is evolved during:

asked Aug 23, 2018 by meena.p

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Oxidation is a process which involves:

asked Aug 23, 2018 by meena.p

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In the reaction : $2H_2S+SO_2\to 2H_2O+ 3S,$ choose the statement which is false ?

asked Aug 23, 2018 by meena.p

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Chemical changes are __________.

asked Aug 21, 2018 by meena.p

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Which of the following statements is not correct?

asked Aug 21, 2018 by meena.p

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Which of the following gives the correct increasing order of acidic strength?

asked Aug 21, 2018 by meena.p

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The symbol (aq) means:

asked Aug 21, 2018 by meena.p

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Ions that do not participate in a chemical reaction are ____ ions

asked Aug 21, 2018 by meena.p

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The activity series of metals is used to determine whether or not a ______ reaction has occurred.

asked Aug 21, 2018 by meena.p

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A reaction that has oxygen as a reactant and usually has carbon dioxide and water as products is a _____ reaction.

asked Aug 21, 2018 by meena.p

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According to the law of conservation of mass, the total mass of the reacting substances is

asked Aug 21, 2018 by meena.p

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Iron + Sulfur $\to$Iron sulfide $[Fe + S \to FeS]$ is an example of

asked Aug 21, 2018 by meena.p

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Acidic hazardous wastes are neutralised with slaked lime, caustic soda or sodium hydroxide.

asked Aug 21, 2018 by meena.p

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Common reagents for neutralising acid wastes are ____

asked Aug 21, 2018 by meena.p

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Glacial acetic acid , pure $HC_2H_2O_2(FW=60.0)$ has concentration of $17.54\;M$ . If $85.5\;mL$ of glacial acetic are diluted to 250 mL. What is the acetic acid concentration ?

asked Aug 16, 2018 by meena.p

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