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Values of heats of formation for SiO(2) ...

Values of heats of formation for `SiO_(2)` and `MgO` are `-48.4` and `-34.7 kJ` respectively. The heat of the reaction `2Mg+SiO_(2)rarr2MgO+Si` is

A

`21.16KJ`

B

`-21.00KJ`

C

`-13.62KJ`

D

`13.6KJ`

Text Solution

Verified by Experts

The correct Answer is:
B
`DeltaH=[2xx(-48.4)+0]-[(-34.7+0)]`
`=-69.4+48.4KJ`
`=-2100KJ`
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