Part one.) estimate the value of the equilibrium constant at 640 k for each of the following reactions. δg∘f for brcl(g) is −1.0 kj/mol. the standard molar entropy, s∘, for brcl(g) is 240.0 j/mol⋅k.
a.) 2no2(g)⇌n2o4(g). δh∘f for n2o4(g) is 9.16 kj/mol.
k= ?
b.) br2(g)+cl2(g)⇌2brcl(g) .δh∘f for brcl(g) is 14.6 kj/mol.
k=?
part two.) estimate the value of the equilibrium constant at 675 k for each of the following reactions. δg∘f for brcl(g) is −1.0 kj/mol. the standard molar entropy, s∘, for brcl(g) is 240.0 j/mol⋅k.
a.) 2no2(g)⇌n2o4(g). δh∘f for n2o4(g) is 9.16 kj/mol.
k= ?
b.) br2(g)+cl2(g)⇌2brcl(g) .δh∘f for brcl(g) is 14.6 kj/mol.
k=?

C. chemical changeshope i : )

The answer is  d.  hydrogen 

Answer

it is the minimum amount of material needed to sustain a fission reaction.

explanation

critical mass is the minimum amount of fissionable material that must be assembled for a sustained fission reaction to take place. although two to three neutrons are produced for every fission, not all of these neutrons are available for continuing the fission reaction. if the conditions are such that the neutrons are lost at a faster rate than they are formed by fission, the chain reaction will not be self-sustaining.   at the point where the chain reaction can become self-sustaining, this is referred to as critical mass.

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