the composition of hydrogen selenide can be determined by heating tin(Sn)in a measured volume of gas the hydrogen selenide is decomposed producing solid tin selenide(SnSe)and hydrogen gas if the temp,and pressyure are unchanged,the gas volume when the decomposition is over is the same as it was to begin with write a balanced chemical equasion for the reaction between hydrogen selenide and tin and why it accounts for the fact that the gas volume is unchanged please help if u can

Question

H2Se(g) + Sn(s) ==> SnSe(s) + H2(g)

We have 1 mol H2Se gas on the left. We have 1 mol H2 gas on the right. One mol of gas as a reactant and 1 mol of gas in the product means the volume doesn't change. Equal mols will occupy equal volumes.

Note the correct spelling of equation.

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