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The enthalpy changes for two reactions a...

The enthalpy changes for two reactions are given by the equations:
`2Cr(s) +(3)/(2)O_(2)(g) rarr Cr_(2)O_(3)(s), DeltaH^(Theta) =- 1130 kJ`
`C(s) +(1)/(2)O_(2)(g)rarr CO(g), DeltaH^(Theta) =- 110 kJ`
What is the enthalpy change in `kJ` for the following reactions?
`3C(s) +Cr_(2)O_(3)(s) rarr 2Cr(s) +3CO(g)`

A

`-1460kJ`

B

`-800kJ`

C

`+800kJ`

D

`+1020kJ`

Text Solution

Verified by Experts

The correct Answer is:
C
`3C(s)+(3)/(2)O_(2)(g)to3CO(g)," "DeltaH=-330kJ`
`Cr_(2)O_(3)(s)to2Cr(s)+(3)/(2)O_(2)(g)," "DeltaH=+1130kJ`
On adding, `underlineoverline(3C(s)+Cr_(2)O_(3)(s)to2Cr(s)+3CO(g)," "DeltaH=800kJ)`
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