Properties of Enthalpy

Q.

How do you tell if a reaction is exothermic or endothermic?

Q. The correct order of decreasing bond energy is-(1) O-O> S- S> Se - Se(2) C - C> Si - Si > Ge - Ge(3) F - F> O-O >N-N(4) F - F> Cl - Cl> Br - Br give detailed explanati

Q. 65. Correct order of bond energy is 1)I-Cl less than I2 2) Br-F greater than F2 3)Br-F less than I2 4)F2 less than Cl2 4). infinity

Q.

On which of the following factors the enthalpy change of a reaction is NOT dependent?

1. Enthalpy of reactants and products

2. State of reactants and products

3. Various intermediate reactions

4. Nature of reactants and products

Q. For the combustion of 1 mole of a liquid benzene at ${25}^{o}C$, the enthalpy is given by:
$C_6{H}_6\left(l\right)+\frac{15}{2}{O}_2\left(g\right)\to 6C{O}_2\left(g\right)+3H_{2}O\left(l\right)$ $\Delta H=-780980$ cal
What would be the internal energy of the reaction?

1. $780kcal$
2. $-780kcal$
3. $580kcal$
4. $-580kcal$

Q.

Expressed in SI units, when the universal gas constant (R) is divided by Avogadro’s number (N), we get:

1. Planck’s constant

2. Rydberg’s constant

3. Boltzmann’s constant

4. Stefan-Boltzmann constant

Q. The enthalpy change for a reaction does not depend upon

1. Use of different reactants for the same product

2. The nature of intermediate reaction steps

3. The differences in initial or final temperatures of involved substances

4. The physical states of reactants and products

Q. When one mole of an ideal gas is compressed to half of the initial volume and simultaneously heated to twice of its initial temperature, the change in enthalpy $\left(\Delta S\right)$ is (Considering the process to be isobaric)

1. $C_{v}ln2$
2. $C_{p}ln2$
3. $Rln2$
4. $(C_v-R)ln2$

Q. Under which of the following conditions is the relation,
$\Delta H=\Delta U+P\Delta V$
valid for a closed system.

1. At constant pressure
2. At constant volume
3. At constant temperature
4. At constant volume and pressure

Q. 43. Why bond energy of C_C is more than N_N .C_C bond energy should decrease as c is gr14element and its size is more than N so bond length in case ofC should be more and bond energy less than N

Q.

The dissociation energy of methane is 360 kcal/mol and that of ethane is 620 kcal/mol.The C-C bond energy is??

Q. When one mole of an ideal gas is compressed to half of the initial volume and simultaneously heated to twice of its initial temperature, the change in enthalpy $\left(\Delta S\right)$ is (Considering the process to be isobaric)

1. $C_{v}ln2$
2. $C_{p}ln2$
3. $Rln2$
4. $(C_v-R)ln2$