Ethanol is added to gasoline because the oxygen it contains improves gasoline's burning efficiency. Its combustion reaction is given below. CH3CH2OH(l) + 3O2(g) → 2CO2(g) + 3H2O(g) ∆H = - 1236 kJ a) Is this an exothermic or endothermic reaction? b) If 15.3 grams of pure ethanol is completely converted to products, calculate how much heat is absorbed or released, in: (1) kJ and in (2) kcal c) If 42.7 g of water vapor is produced, how much heat, in kJ, is absorbed or released?

Plz mark brainliest 30 points 1) find the momentum of a 12 kg snowball that is rolling with a velocity of 9 m/s. 2) an 8 ball with a mass of .5 kg is sitting at rest. it is hit by the cue ball (1 kg) traveling at 2.5 m/s. if the cue ball is at rest after the collision, how fast is the 8 ball traveling after the collision? 3) two football players are running toward each other. if the offensive player is 75 kg and is running 8 m/s, how fast must the 60 kg defensive player run in order for the two players to hit and stop?

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

Akno3 solution containing 51 g of kno3 per 100.0 g of water is cooled from 40 ∘c to 0 ∘c. what will happen during cooling?