Chemistry-

General

Easy

Question

# Enthalpy change for the reaction, 4H_{(g)} →2H_{2(g)} is–869.6kJ The dissociation energy of H–H bond is

- +217.4kJ
- –434.8kJ
- –869.6kJ
- +434.8kJ

## The correct answer is: +434.8kJ

### Related Questions to study

chemistry-

### ThevaluesofDHandDSforthereaction,C(graphite)+CO(g)→2CO(g)are170kJand170 JK–1respectively.Thisreactionwillbespontaneousat

### ThevaluesofDHandDSforthereaction,C(graphite)+CO(g)→2CO(g)are170kJand170 JK–1respectively.Thisreactionwillbespontaneousat

chemistry-General

maths-

### Assertion: The sum of all4 digited numbers that can be formed using the digits 1,2,4,5,6 without repetition is 479952

Reason: Sum of all ‐digit numbers formed by taking the given n digits (without zero) is (sum of all the n digits) ( times).

### Assertion: The sum of all4 digited numbers that can be formed using the digits 1,2,4,5,6 without repetition is 479952

Reason: Sum of all ‐digit numbers formed by taking the given n digits (without zero) is (sum of all the n digits) ( times).

maths-General

maths-

### Assertion: There are three doors to a room The number of ways in which a student can enter the room and leave it by a different door is 6.

Reason: If an operation can be performed in ways and another operation can be perfO rmed in ways thenthe two operations in succession can be performed in mn ways.

### Assertion: There are three doors to a room The number of ways in which a student can enter the room and leave it by a different door is 6.

Reason: If an operation can be performed in ways and another operation can be perfO rmed in ways thenthe two operations in succession can be performed in mn ways.

maths-General

maths-

### Assertion(A): The number of quadratic expressions with the coefficients drawn from the set {0,1,2,3} is only 48 but not 64.

Reason(R): The coefficient inthe quadratic expression can not be ’

### Assertion(A): The number of quadratic expressions with the coefficients drawn from the set {0,1,2,3} is only 48 but not 64.

Reason(R): The coefficient inthe quadratic expression can not be ’

maths-General

maths-

### Assertion (A) : The number of ways of arranging 6 boys and 5 girls alternately at circular table is Reason (R) : To arrange boys and girls alternately at a circular table, they should be equal in number.

### Assertion (A) : The number of ways of arranging 6 boys and 5 girls alternately at circular table is Reason (R) : To arrange boys and girls alternately at a circular table, they should be equal in number.

maths-General

chemistry-

### GivenenthalpyofformationofCO2(g)andCaO(s) are–94.0KJand–152KJrespectivelyandthe enthalpyofthereaction-CaCO3(s) →CaO(s)+CO2(g) is42KJ.The enthalpyofformationofCaCO3(s)

### GivenenthalpyofformationofCO2(g)andCaO(s) are–94.0KJand–152KJrespectivelyandthe enthalpyofthereaction-CaCO3(s) →CaO(s)+CO2(g) is42KJ.The enthalpyofformationofCaCO3(s)

chemistry-General

chemistry-

### Change in entropy is negative for–

### Change in entropy is negative for–

chemistry-General

chemistry-

### The enthalpychange(DH) forthereaction,N2(g) +3H2(g) 3/4 →2NH3(g)is–92.38KJat 298K.TheinternalenergychangeDUat298Kis-

### The enthalpychange(DH) forthereaction,N2(g) +3H2(g) 3/4 →2NH3(g)is–92.38KJat 298K.TheinternalenergychangeDUat298Kis-

chemistry-General

chemistry-

### For a phase change H_{2}O(l) H_{2}O(s)M

### For a phase change H_{2}O(l) H_{2}O(s)M

chemistry-General

chemistry-

### The absolute enthalpy of neutral is ation of the reaction: MgO(s)+2HCl(aq)3/4→MgCl2(aq)+H2O(l) will be-

### The absolute enthalpy of neutral is ation of the reaction: MgO(s)+2HCl(aq)3/4→MgCl2(aq)+H2O(l) will be-

chemistry-General

chemistry-

### For which one of the following equations is D H reaction equal to DH° for the product-

### For which one of the following equations is D H reaction equal to DH° for the product-

chemistry-General

Maths-

### When a die is rolled twice, if the event of getting an even number is denoted by a success and the number of successes as a random variable, then distribution and mean of the variate are

### When a die is rolled twice, if the event of getting an even number is denoted by a success and the number of successes as a random variable, then distribution and mean of the variate are

Maths-General

chemistry-

### Enthalpy of CH4+ O2→CH3OH is negative. If enthalpy of combustion of CH4 and CH3OH are x and y respectively. Then which relation is correct-

### Enthalpy of CH4+ O2→CH3OH is negative. If enthalpy of combustion of CH4 and CH3OH are x and y respectively. Then which relation is correct-

chemistry-General

chemistry-

### Change in enthalpy for reaction 2H2O2(l) → 2H2O(l)+O2(g) If heat of formation of H2O2 (l) and H2O (l)are– 188&–286KJ/mol respectively

### Change in enthalpy for reaction 2H2O2(l) → 2H2O(l)+O2(g) If heat of formation of H2O2 (l) and H2O (l)are– 188&–286KJ/mol respectively

chemistry-General

chemistry-

### For there action C2H5OH(l)+3O2(g)→2CO2(g)+3H2O(l) Which one istrue -

### For there action C2H5OH(l)+3O2(g)→2CO2(g)+3H2O(l) Which one istrue -

chemistry-General