2Fe(s) + 32 O2(g)→Fe2O3(s) (△

Sail E0 Webinar

Question

2 F e (s) + \frac{3}{2} O_{2} (g) \to F e_{2} O_{3} (s) (△ H = - 193.4 k J) . . . . . . (1)

M g (s) + \frac{1}{2} O_{2} (g) \to M g O (s) (△ H = - 140.2 k J) . . . . . . (2)

What is

△

∆H of the reaction?

3 M g + F e_{2} O_{3} \to 3 M g O + 2 F e

Options:

A . -272.3 kJ

B . 272.3 kJ

C . 272.2 kJ

D . -227.2 kJ

Answer: Option D
:
D
Equation (2) is multiplied by 3

2 F e (s) + \frac{3}{2} O_{2} (g) \to F e_{2} O_{3} (s) △ H = - 193.4 k J . . . . . . (1)

3 M g (s) + \frac{3}{2} O_{2} (g) \to 3 M g O (s) △ H = - 420.6 k J . . . . . . (3)

Subtracting equation (1) from (3)

3 M g (s) + F e_{2} O_{3} \to 3 M g O + 2 F e △ H = - 420.6 - (- 193.4)

= -227.2 kJ

Was this answer helpful ?

Next Question

Submit Solution

More Questions on This Topic :

Question 1. The enthalpy change for the reaction of 50.00 ml of ethylene with 50.00 ml of H2 at 1.5 atm pressure is 9....ΔH− = -0.31 kJ. The value of ΔE will be

Question 2. A well stopped thermos flask contains ice cubes. This is an example of....

Question 3. Two moles of an ideal gas is expanded isothermally and reversibly from 1 litre to 10 litre at 300 K. The enthalpy change....The enthalpy change ( in kJ) for the process is

Question 4. An ideal gas expands in volume from 1 × 10−3 to 1 × 10−2 m3 at 300 ....against a constant pressure of 1 × 105 Nm−2. The work done is

Question 5. The dissociation energy of CH4 is 400 Kcal mol−1 and that of ethane is 670 Kcal mol−1. The C - C bond ener....670 Kcal mol−1. The C - C bond energy is.

Question 6. The standard enthalpies of formation of CO2(g), H2O(l) and glucose(s) at 25∘C are −400 kJ/mol, ȡ....enthalpy of combustion per gram of glucose at 25∘C is

Question 7. In a process a system does 140 J of work on the surrondings and only 40 J of heat is added to the system, hence change i....added to the system, hence change in internal energy is

Question 8. Which of the following is /are true in the case of an adiabatic process....

Question 9. The enthalpies for the following reactions at 25°C are given. 12 H2(g) + 12 O2(g)→OH(g);....the OH bond energy in the O - H group

Question 10. The heat of combustion of yellow phosphorous & red phosphorous are - 9.91 KJ and - 8.78 KJ respectively. The h....heat of transition of yellow phosphorous to red phosphorous is:

Chapter 1 - GLOBAL STEEL SCENARIO & INDIAN STEEL INDUSTRY Part 1 : (13-04-2024) INDUSTRY AND COMPANY AWARENESS (ICA)

Direction Sense Test Part 1 Reasoning (Hindi)

Chapter 1 - RMHP / OHP / OB & BP Part 1 : (14-02-2024) GPOE

Cube & Cuboid Part 1 Reasoning (Hindi)

Data Interpretation (DI) Basic Concept Reasoning (Hindi)

Counting Figures Part 1 Counting Of Straight Lines Reasoning (Hindi)

Sail E0 free webinar Webinars

Real Numbers Part 7 Class 10 Maths

Real Numbers Part 1 Class 10 Maths

Polynomials Part 1 Class 10 Maths

DSP Combined 1 Free Revision Test SAIL JO E-0

GPOE / GPA Combined 1 Free Revision Test SAIL JO E-0

BSP Plant Specific Review Test SAIL JO E-0

BSL Combined 1 Free Revision Test SAIL JO E-0

GFM Combined 1 Free Revision Test SAIL JO E-0