If 3 moles of a compound use 24 J of energy in a reaction, what is the A
Hreaction in J/mol?

+8 J/mol

Explanation:

The following were obtained from the question:

Mole of the compound = 3 moles

Heat Energy used = 24J

Hreaction =?

The heat of reaction is the energy released or absorb during a chemical reaction. It is can obtained mathematically by the following equation:

Hreaction = Heat energy/mole

With the above equation, we can easily find the Hreaction for the question given as follow:

Hreaction = Heat energy/mole

Hreaction = 24J / 3mol

Hreaction = 8 J/mol

Since the compound used the energy, the Hreaction is +8 J/mol

6.4 cm (max) - 25 cm (min)

(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