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?
If the mass of an object is 30 grams and the volume is 200mL. Will the object sink or float in water?
float
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...
In a chemical reaction matter can not be created or destroyed, thus the mass is the same before and after. Marcus found the mass of the reactant to be 47 grams. He found the mass of the products to be 41 grams. Under the assumption that there were no errors, why does the mass before and after not the same?
The reaction took place in a open system. Some of the matter was a gas that escaped.
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?
Moby thinks that if he put lead and water together it will react to make gold. Lead is Pb on the periodic table, Gold is Au. Here is the reaction he thinks will take place:
Pb + H20 ---> Au
Why is this NOT POSSIBLE?
For Au - Gold to be made, then there must be Au atoms in the reactants.
Moby only has H- hydrogen, O- Oxygen, and Pb - Lead.
Marsha is unsure if a chemical reaction has occurred. She collected some data about the before and after. She concluded that the before and after have the same density, same hardness, and same boiling point temperature. However, the shape is different.
Did a chemical reaction occur? Explain.
No, all the properties are all the same, so it is the same substance before and after. The shape only changes the appearance. Each substance has its own specific properties.
This is the term for a compound that has subscripts, symbols and maybe coefficients.
What is a chemical formula?
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?