#color(white)(mmmmmmmll)"N≡N" + 2"H-H"→ color(white)(m)"H"_2"N-NH"_2#
#"Bonds:"color(white)(mmml) "1 N≡N" + "2 H-H" color(white)(ml)"4 N-H" + "1 N-N"#
#BE"/kJ·mol"^"-1":color(white)(m)946color(white)(mmll)436color(white)(mmll)389color(white)(mmll)163#
The formula for #Δ_text(f)H# is
#color(blue)(bar(ul(|color(white)(a/a)Δ_text(f)H = sumBE_text(reactants) - sumBE_text(products)color(white)(a/a)|)))" "#
#sumBE_text(reactants) = "[(1×946) + (2×436)] kJ" = "(946 + 872) kJ" = "1818 kJ"#
#sumBE_text(products) = "[(4×389) + (1×163)] kJ" = "(1572 + 163) kJ" = "1719 kJ"#
#Δ_text(f)H = "1818 kJ - 1719 kJ = 99 kJ/mol"#
The reaction is endothermic.
