Answer:
Chemical energy obtained from the breakdown of food molecules.
Answer :
Charles's Law : It is defined as the volume is directly proportional to the temperature of the gas at constant pressure and number of moles.
Mathematically,

Boiling water bath Cool bath 1 Cool bath 2
Temperature (⁰C) 99 17 2
Temperature (K)(T) 273+99=372 273+17=290 273+2=275
Volume of water 0.0 27.0 34.0
in cool flask (mL)
Volume of water= 135.8 135.8 135.8
Air in flask (mL)
Volume of air 135.8 108.8 101.8
in cool flask (V)

The graph volume versus temperature for a gas is shown below.
Answer:
2HClO4(aq) + Ca(OH)2(aq) → Ca(ClO4)2(aq) + 2H2O(l)
Perchloric acid + Calcium hydroxide → Calcium perchlorate + Water.
Explanation:
This is a neutralization reaction where the acid, Perchloric acid reacts completely with an appropriate amount of base, aqueous Calcium hydroxide to produce salt, aqueous Calcium perchlorate and water, liquid H2O only.
During this reaction, the hydrogen ion, H+, from the HClO4 is neutralized by the hydroxide ion, OH-, from the Ca(OH)2 to form the water molecule, H2O.
Thus, it is called a neutralization reaction.
The percent composition of this compound :
Mg = 72.182%
N = 27.818%
<h3>Further explanation</h3>
Given
9.03 g Mg
3.48 g N
Required
The percent composition
Solution
Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements
Total mass of the compound :
= 9.03 g + 3.48 g
= 12.51 g
The percent composition :
Mg : 9.03/ 12.51 g x 100% = 72.182%
N : 3.48 / 12.51 g x 100% = 27.818%