Chemical Equations
The substance you start with in a chemical reaction. They are the molecules on the left side of the arrow.
______?_____ ---> _________ + _________
What are Reactants?
How many TOTAL atoms?
2Li3O2
10
Johnny has 12 grams of baking soda and 12 grams of vinegar. In the end of the experiment she should have ____________ grams.
What is 24 grams of product?
List 2 clues/evidence that a chemical reaction has occurred.
Answer will vary.
- heat or light released or absorbed (energy)
- new substance forms -gas or bubbles form
-Temperature change -color change
Explain what happens to the atoms and compounds during a chemical reaction to form new substances.
The molecules break their bonds between the atoms. The atoms then rearrange to form the new substances.
CH3 + 2O2 ----> CO2 + 2H2O
In the chemical equation above, what are the products?
CO2 or H2O
How many OXYGEN atoms are in the reactants?
CO2 + 2 NaOH ---> Na2CO3 + H2O
What is 4?
Bonus: Is this equation balanced? Show how...
Zn + HCl ---> ZnCl + H
If there are 22 grams of Zn, 50 grams of HCl, and 11 grams of H. How many grams of ZnCl ?
What is 61 grams?
Chemical or Physical Change?
A cake baking in an oven
Chemical
If there are 12 total atoms in the reactants, how many atoms will be in the products?
12
How many TOTAL atoms are in the PRODUCTS?
CO2 + 2 NaOH ---> Na2CO3 + H2O
What is 9?
Bonus: Is this equation balanced? Show how...
C3 + 5 O2 ----> 4 H2O + 3CO2
List the reactants
List the products
Reactants: C3 + 5 O2
Products: 4 H2O + 3CO2
Look at the following chemical equation. How many atoms of hydrogen or H are there?
5H3C2O4
What is 15?
What is a possible product for these reactants?
MgOH + H2O ---> ______?_________
Answers will vary. Must have:
1 Mg
2 O
3 H
How many TOTAL atoms?
2MgOH2
what is 8?
A chemical reaction produces two new substances, and each product has a mass of 25 grams. What was the total mass of the reactants?
50 grams
In making a pizza, which process involves a chemical change?
a) baking the dough to form the crust
b) slicing pepperoni for the topping
c) spreading cheese on the pizza
d) mixing spices for the sauce
a) baking the dough to form a crust
What is the difference between a physical and a chemical change?
Physical changes do not create new matter, whereas chemical changes do.
This is the part of the atom that helps bond to other atoms forming a compound or molecule.
What are bonds?
Look at the following equation: What is the coefficient in the equation?
H2O2 + 4HCl + H2
What is 4?
Bonus: How many atoms of H are there?
Name the three subatomic particles in an atom.
What is electron, proton, neutron?