For changing potential energy; When you drop a book, gravitational potential energy is transformed into kinetic energy. Your car transforms the chemical potential energy stored in gasoline into the kinetic energy of the car's motion.
For Kinetic Energy; kinetic energy can be converted into electrical energy by a generator or into thermal energy by the brakes on a car.
Answer:

Explanation:
mass of Fe = 55.85 g
Molar mass of Fe = 55.85 g/mol
<u>Moles of Fe = 55.85 / 55.85 = 1</u>
mass of Cl = 106.5 g
Molar mass of Cl = 35.5 g/mol
Moles of Cl = 106.5 / 35.5 = 3
Taking the simplest ratio for Fe and Cl as:
1 : 3
The empirical formula is = 
Explanation:
(a) potassium oxide with water

According to reaction,1 mole of potassium oxide reacts with 1 mole of water to give 1 mole of potassium hydroxide.
(b) diphosphorus trioxide with water

According to reaction,1 mole of diphosphorus trioxide reacts with 2 moles of water to give 2 moles of phosphorus acid.
(c) chromium(III) oxide with dilute hydrochloric acid,

According to reaction,1 mole of chromium(III) oxide reacts with 6 moles of hydrochloric acid to give 2 moles of chromium(III) chloride and 3 moles of water.
(d) selenium dioxide with aqueous potassium hydroxide

According to reaction,1 mole of selenium dioxide reacts with 2 moles of potassium hydroxide to give 1 mole of potassium selenite and 1 mole of water.
This is a one-step unit analysis problem. Since we are staying in moles, grams of our compound, and thus molar mass, is not needed.
1 mole is equal to 6.022x10²³ particles as given, so:

<h3>
Answer:</h3>
2.49 mol
Let me know if you have any questions.