Which of the following reactions have a positive ΔSrxn? Check all that apply

Which of the following reactions have a positive ΔSrxn? Check all that apply.

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Answer:

In the reactions

A(g) + B(g)------- 3C(g)
2A(g) + B(s)-------3C(g)

the number of moles increases, volume increases,so disorder of the molecules increases in the product side for third and fourth reactions so ΔSrxn is positive.