<u>Answer:</u>
<em>The amount of energy needed when water at 72 degrees c freezes completely at 0 degrees c is 
Joules</em>
<em></em>
<u>Explanation:</u>
where
= Final T - Initial T
=30125J
Q is the heat energy in Joules
c is the specific heat capacity (for water 1.0 cal/(g℃)) or 4.184 J/(g℃)
m is the mass of water
mass of water is assumed as 100 g (since not mentioned)
is the heat energy required for the phase change
=mass × heat of fusion
Total heat = 
Total Heat = 30123J + 33600J
= 63725 J
= Joules is the answer
Answer:
Molar mass = 216.8254 (approx.)
Explanation:
Given:
FeCl2 • 5H20
Find:
Molar mass
Computation:
Atomic mass
Fe = 55.845
Cl = 35.453
H = 1.00794
So,
FeCl2 • 5H20
55.845 + 2(35.453) + (2)5(1.00794) + 5(15.999)
55.845 + 70.906 + 10.0794 + 79.995
Molar mass = 216.8254 (approx.)
Air, glass, plastic, wood, rubber are good insulators
What is the percent by mass of sodium in Na2SO4? total mass of element in compound molar mass of compound Use %Element x 100
Answer:
If the discs floated, they produced oxygen and gained buoyancy.
