C3H8 + 5O2 -> 3CO2 + 4H2O a) If you used 3 moles of O2, how many moles of H2O would be produced? b) If you used 3.5 moles of C3H8, how many grams of CO2 would be produced? c)If you used 230g of O2, how many grams of H2O would be produced?

i'm assuming that the correct answer is indeed the first one/ "a"..

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied