Enthalpies for Different Types of Reactions

What is the enthalpy change for,

$2{\mathrm{H}}_2{\mathrm{O}}_2\left(\mathrm{l}\right)\to 2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$ if heat of formation of  ${\mathrm{H}}_2{\mathrm{O}}_2\left(\mathrm{l}\right)\mathrm{and}{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$  are $-188$ and $-286 \mathrm{kJ}/\mathrm{mol}$respectively (in standard conditions)?

The enthalpy changes at $298 \mathrm{K}$ in successive breaking of $\mathrm{O}-\mathrm{H}$ bonds of water are-
${\mathrm{H}}_2\mathrm{O} \to \mathrm{H}\left(\mathrm{g}\right)+\mathrm{OH}\left(\mathrm{g}\right); ∆\mathrm{H}= 498 \mathrm{kJ} {\mathrm{mol}}^{-1}$
$\mathrm{OH} \to \mathrm{H}\left(\mathrm{g}\right)+\mathrm{O}\left(\mathrm{g}\right); ∆ \mathrm{H}= 428 \mathrm{kJ} {\mathrm{mol}}^{-1}$
The bond enthalpy of $\mathrm{O}-\mathrm{H}$ bond is
 

The enthalpy change that accompanies melting of one mole of a solid substance in standard state is called enthalpy of atomization.

What is the difference between heat of solution and heat of dilution?

The integral heat of dilution is viewed on a macro scale.

The _____ heat/enthalpy of dilution is viewed on a micro scale.

The lattice enthalpy and hydration enthalpy of four compounds are given below:

The pair of compounds which is soluble in water is

The amount of energy released in burning $1\mathrm{kg}$ of coal is

Match the column I with column II and mark the appropriate choice.

Define and explain enthalpy of atomization with an example.

Calculate the enthalpy change for the reaction,

${\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)⟶2\mathrm{H}\left(\mathrm{g}\right)+\mathrm{O}\left(\mathrm{g}\right)$ and hence, calculate the bond enthalpy of $O-\mathrm{H}$
bond in ${\mathrm{H}}_2\mathrm{O}$ from the following data;

${\mathrm{\Delta }}_{\mathrm{vap}}\mathrm{H}\left({\mathrm{H}}_2\mathrm{O}\right)=44.0{\mathrm{kJmol}}^{-1}$

${\mathrm{\Delta }}_{\mathrm{f}}\mathrm{H}\left({\mathrm{H}}_2\mathrm{O}\right)=-285.8{\mathrm{kJmol}}^{-1}$

$\begin{array}{l}{\Delta }_{\mathrm{a}}\mathrm{H}\left({\mathrm{H}}_2\right)=436.0{\mathrm{kJmol}}^{-1},{\Delta }_{\mathrm{a}}\mathrm{H}\left({\mathrm{O}}_2\right)=498.0\mathrm{kJ}\\ {\mathrm{mol}}^{-1}\end{array}$

where ${∆}_{\mathrm{a}}\mathrm{H}$ is the enthalpy of atomization.
 

Given, ${\text{N}}_2\left(\text{g}\right)+3{\text{H}}_2\left(\text{g}\right)\to 2{\text{NH}}_3\left(\text{g}\right)\text{;}{\Delta }_{\text{r}}{\text{H}}^{\circ }=-92·4\text{kJ}{\text{mol}}^{-1}$

What is the standard enthalpy of formation of NH₃ gas in KJ mole^-1.

Which of the following is not a correct statement about enthalpy of solution?

Study the figure given below and mark the correct expression.

The enthalpy of solution of $\mathrm{X}{\mathrm{Y}}_{\left(\mathrm{s}\right),}\mathrm{\Delta }{\mathrm{H}}_{\mathrm{s}\mathrm{o}\mathrm{l}\mathrm{n}.}^{°}$ In water can be determined by

$∆\mathrm{H}$ for the reaction, $\mathrm{O}{\mathrm{F}}_2+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{O}}_2+2\mathrm{H}\mathrm{F}$
( $\mathrm{B}.\mathrm{E}.$ of $\mathrm{O}-\mathrm{F}$ , $\mathrm{O}-\mathrm{H}$ , $\mathrm{H}-\mathrm{F}$ and $\mathrm{O}=\mathrm{O}$ are $44,\mathrm{ }111,\mathrm{ }135$ and $119\mathrm{ }\mathrm{k}\mathrm{c}\mathrm{a}\mathrm{l}\mathrm{ }\mathrm{m}\mathrm{o}{{\mathrm{l}}^{-}}^1$ respectively)

For the reaction, $2{\mathrm{H}}_2+{\mathrm{O}}_2\to 2{\mathrm{H}}_2\mathrm{O, }$$\Delta \text{H}=-571\text{KJ}$. Bond energy of $\mathrm{H}-\mathrm{H}=435\mathrm{KJ},\mathrm{O}=\mathrm{O}=498\mathrm{KJ}$, then calculate the average bond energy of $\mathrm{O}-\mathrm{H}$ bond using the above data (Give the nearest integer answer, in ${\mathrm{KJmol}}^{-1}$)

A triatomic linear (neglect vibration degree of freedom) gas of two moles is taken through a reversible process, ideally starting from A as shown in figure.
The volume ratio $\frac{{\text{V}}_{\text{B}}}{{\text{V}}_{\text{A}}}=4$. If the temperature at A is $-73^{\circ }\text{C}$ :



Total enthalpy change in both steps in cal/mol is :

If the bond energies of $\mathrm{H}-\mathrm{H},\mathrm{ }\mathrm{B}\mathrm{r}-\mathrm{B}\mathrm{r},\mathrm{ }\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{ }\mathrm{H}-\mathrm{B}\mathrm{r}\mathrm{ }\mathrm{a}\mathrm{r}\mathrm{e}\mathrm{ }433,\mathrm{ }192\mathrm{ }\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{ }364\mathrm{ }\mathrm{k}\mathrm{J}\mathrm{ }\mathrm{m}\mathrm{o}{\mathrm{l}}^{-1}$ respectively, the $∆{\mathrm{H}}^{\mathrm{o}}$ for the reaction ${\mathrm{H}}_2\left(\mathrm{g}\right)+\mathrm{B}{\mathrm{r}}_2\left(\mathrm{g}\right)\to 2\mathrm{H}\mathrm{B}\mathrm{r}\left(\mathrm{g}\right)$ is

500 ml of 1 M HCN is neutralized completely by 500 ml of 1 M KOH solution and 1.36 K.cal of heat is liberated. The $∆\mathrm{H}$ of dissociation of HCN is

What is the bond enthalpy of Xe - F bond if Ionization energy of $\mathrm{X}\mathrm{e}=279\mathrm{ }\mathrm{k}\mathrm{c}\mathrm{a}\mathrm{l}/\mathrm{m}\mathrm{o}\mathrm{l}\mathrm{ }\mathrm{B}.\mathrm{E}.(\mathrm{F}-\mathrm{F})=38\mathrm{ }\mathrm{k}\mathrm{c}\mathrm{a}\mathrm{l}/\mathrm{m}\mathrm{o}\mathrm{l}$ , electron affinity of $\mathrm{F}=85\mathrm{ }\mathrm{k}\mathrm{c}\mathrm{a}\mathrm{l}/\mathrm{m}\mathrm{o}\mathrm{l}$