The reaction between ammonia, oxygen and methane yield Hydrogen cyanide and the other product water. If the reaction vessel contains 11.5g,12.0g,10.5g of ammonia,oxygen and methane respectively,what is the maximum mass in gram of the cyanide that could ?

The maximum mass of hydrogen cyanide that could form is 6.76 g.

This is a limiting reactant problem, so we calculate the amount of ##"HCN"## that we can get from each reactant.

The balanced chemical equation is

##"2NH"_3 + "3O"_2 + "2CH"_4→ "2HCN" + "6H"_2"O"##

From ##"NH"_3##:

##"Moles of HCN" = 11.5 cancel("g NH₃") × (1 cancel("mol NH₃"))/(17.03 cancel("g NH₃")) × "2 mol HCN"/(2 cancel("mol NH₃")) = "0.675 mol HCN"##

From ##"O"_2##: ##"Moles of HCN" = 12.0 cancel("g O₂") × (1 cancel("mol O₂"))/(32.00 cancel("g O₂")) × "2 mol HCN"/(3 cancel("mol O₂")) = "0.250 mol HCN"##

From ##"CH"_4##:

##"Moles of HCN" = 10.5 cancel("g CH₄") × (1 cancel("mol CH₄"))/(16.04 cancel("g CH₄")) × "2 mol HCN"/(2 cancel("mol CH₄")) = "0.655 mol HCN"##

##"O"_2## gives the fewest moles of ##"HCN"##, so ##"O"_2## is the limiting reactant.

##"Mass of HCN" = 0.250 cancel("mol HCN") × "27.03 g HCN"/(1 cancel("mol HCN")) = "6.76 g HCN"##