1) First write a balanced chemical equation
[tex]2\ C_{2} H_{2}_{(g)}[/tex] + [tex]5\ O_{2}_{(g)}[/tex] ---> [tex]4\ CO_{2}_{(g)}[/tex] + [tex]2\ H_{2}O_{(g)}[/tex]
2) Use dimensional analysis to find your answer.
= 30000g [tex]C_{2} H_{2}[/tex] × [tex]\frac{1\ mol\ C_{2}H_{2}}{26.04g\ C_{2}H_{2}}[/tex] × [tex]\frac{2\ mol\ H_{2}O}{2\ mol\ C_{2}H_{2}}[/tex] × [tex]\frac{18.02g\ H_{2}O}{1\ mol\ H_{2}O}[/tex]
= 20760.36866
= 20760g H₂O