For all question, all you need to use is the mole-mole ratio.
a) 25 moles C2H6O (3 moles O2/ 1 mol C2H6O)= 75 moles O2
b) 30 moles O2 (1 moles C2H6O/ 3 moles O2)= 10 moles C2H6O
c) 23 moles CO2 (3 moles O2/ 2 moles CO2) = 34.5 moles O2
d) 41 moles H2O ( 1 moles C2H6O/ 3 moles H2O= 13.7 moles C2H6O
Weathering and erosion produce ever smaller rock particles which,
when mixed with dust and decayed organic matter over time ,
result in different types of soil .
[hope this helps]