Question

consider the following reaction: 2H2+O2=2H2O Hcomb=-572kj how much heat is evolved when 4.03 g hydrogen is reacted with excess oxygen?

Answer 1

\(H_{comb}\) is kJ/mol, right?

convert the mass given (4.03 g) to moles (using \(moles=\dfrac{mass}{Molar\;mass}\))

then multiply by \(H_{comb}\): q= \(H_{comb}\)*moles