When hydrogen peroxide decomposes, what mass of
hydrogen peroxide is needed
in solution to produce 1.6 g of
oxygen gas?

The Molar mass of Oxygen is 32 g/mol

Therefore moles of Oxygen = 1.6/32 =0.05

2 H2O2 = 2 H2O + O2

So, 2 x 0.05 = 0.1 moles of peroxide are needed.

The molar mass of peroxide is 34 g/mol

Mass = moles x Mr = 0.1 x 34 = 3.4g

Although in reality the yield is unlikely to be 100% so a better answer would be “more than 3.4g”

(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