Unit 2: Change it Up! Lesson 1: Chemical Reactions

Question 1

What are the signs of chemical
reactions?

Answer 1

Change in Color.
Formation of a Gas.
Formation of a Precipitate.
Change in Odor.
Change in Temperature.
Something is Burning.
Light is Being Produced.

Question 2

How are chemical reactions modelled?

Answer 2

using chemical equations

Question 3

What is the difference between a chemical formula and a chemical equation?

Answer 3

A chemical formula tells us the number of atoms of each element in a compound.

Chemical equations are the symbolic representation of chemical reactions.

Question 4

How do chemical equations show the
law of conservation of mass?

Answer 4

law of conservation of mass: atoms cannot be created or destroyed
A balanced chemical equation always obeys law of conservation of mass. According to this law the mass of products must be equal to the mass of reactants.

Question 5

What happens to energy during
chemical reactions?

Answer 5

Energy is either released when the chemical bond breaks the energy stored inside the bond will get released (exothermic). or energy might get absorbed and stored back into the chemical bond (endothermic) EX: candles

Question 6

What affects the rate of reaction?

Answer 6

reactant concentration, surface area (the area will get more exposed to the reactants therefore the reaction will happen faster due to more collisions), temperature (increasing the temperature will make more collisions leading to faster reactions), and catalysts( any substance that increases the rate of a reaction without itself being consumed.)