Answer:
5. All of the above.
Explanation:
Energy can be extracted from water by gravitational force as done in hydroelectric plants, temperature gradients that creates natural convection processes, the mechanical variations of ocean currents and surface waves, and by nuclear fussion.
Answers:
See below
Step-by-step explanation:
1. Most food energy
(a) Pringles
Heat from Pringles + heat absorbed by water = 0
m₁ΔH + m₂CΔT = 0
1.984ΔH + 100 × 4.184 × 18 = 0
1.984ΔH + 7530 = 0
ΔH = -7530/1.984 = -3800 J/g
(b) Cheetos
0.884ΔH + 418.4 × 13 = 0
ΔH = -5400/0.884 = -6200 J/g
Cheetos give you more food energy per gram.
(c) Snickers
Food energy = 215 Cal/28 g × 4184 J/1 Cal = 32 000 J/g
The food energy from Cheetos is much less than that from a Snickers bar
2. Experimental uncertainty
The experimental values are almost certainly too low.
Your burning food is heating up the air around it, so much of the heat of combustion is lost to the atmosphere.
3. Percent efficiency
Experimental food energy = 3800 J/g
Actual food energy = 150 Cal/28 g × 4184 J/1 Cal = 22 000 J/g
% Efficiency = Experimental value/Actual value × 100 %
= 3800/22 000 × 100 %
= 17 %
Atomic mass Nickel ( Ni) = 58.69 a.m.u
1 mole ------------- 58.69 g
2.63 moles -------- ??
2.63 x 58.69 / 1 => 154.3547 g
1 g ------------- 1000 mg
154.3547 g ---- ??
154.3547 x 1000 / 1
=> 154,354.7 mg
The balanced chemical reaction is given as:
Now, convert 
into litres.
So, 
Density is equal to the ratio of mass to the volume.
where, M = mass and V= volume 
Substitute the value of density and volume in formula to get the value of mass.
Now, number of moles of 
gas=
= 
According to the reaction, 2 moles of sodium azide gives 3 moles of nitrogen gas.
Now, in 24.00 moles of nitrogen gas produced from= 
of nitrogen gas, moles of sodium azide.
number of moles of sodium azide = 
Mass of sodium azide in g = 
.
= 
= 
Thus, mass of sodium azide which is required to produce of nitrogen gas =
