[填空题]
Liquid butanol $(C_4H_9OH)$ burns or combusts in oxygen to produce $CO_{2(g)}$ and $H_2O$(g).
1.Write a balanced equation, including state symbols, for this reaction.
2.When $1.250cm^3$ of butanol is combusted in excess oxygen,$1.921dm^3$ of water vapor is collected at a pressure of 125.0 kPa and $150.0^{\circ}C$. Calculate the moles of butanol that were combusted. mol
3.Determine the density of liquid butanol in $g\:cm^{-3}$. g $cm^{-3}$