Complete the table below identifying the different variables for each reaction. Remember, controlled variables are factors that remain the same throughout the experiment An independent (test) variable changes so that the experimenter can see the effect on other
variables. The dependent (outcome) variable will change in response to the test variable.
Reactants
Controlled Variables
Independent Variables
Dependent Variable
A) Iron (III) and copper
(11) sulfate solution
B) Lead (II) nitrate and
potassium iodide
solutions
C) Magnesium metal and
hydrochloric acid solution
D) Electrolysis of water
E) Burning magnesium

(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