Question

26. Consider the following reactions C (graphite) + O2(g)CO2(g) : H = – x1 cal C (diamond) + O2(g) CO2(g) : H = – x2 cal What is the heat of transition of graphite into diamond? (1) x1 + x2 (2) x2 – x1 (3) x1 – x2 (4) x1x2 Sol. Answer (2)

Answer 1

answer : option (2)x2 - x1

explanation : we have to find heat of transition of graphite into diamond.

i.e., C( graphite ) ⇔C( diamond )

given,

C(graphite) + O2(g) ⇒CO2(g) ; ∆H1 = - x1 cal......(1)

C(diamond) + O2 ⇒CO2(g) ; ∆H2 = -x2 cal ......(2)

reverse the equation (2)

CO2(g) ⇒C(diamond) + O2(g) ; ∆H2' = x2 cal .......(3)

now add equations (1) and (3),

C(graphite) + O2(g) + CO2(g) ⇒CO2(g) + C(diamond) + O2(g) ; ∆H = ∆H1 + ∆H2'

or, C(graphite) ⇒C(diamond) ; ∆H = -x1 + x2 = x2 - x1

hence, option (2) x2 - x1 is correct choice.

also read similar questions :Number of molecules in 100 ml of each of O2 , NH3 and CO2 at STP are

options

(a) in the order CO2 < O2<NH3

(b) In o...

https://brainly.in/question/3511961

Determine delta H at 298K for the reaction C(graphite)+2H2(g)------> CH4(g)

Given: C(graphite)+O2(g) CO2(g) delta H=-39...

https://brainly.in/question/7288508

Answer 2

Answer:

x2- x1

Explanation:

Cgraphite + 02 -> CO2(g) H=-x1cal

+ Cdiamond + 02 -> CO2(g) H=-x2 cal

= C graphite + Cdiamond +202->2C02 - X 1 + -x2

Cgraphite -> C diamond = x2 - x1