Balancing Chemical Equations- pretest

What does the Law of Conservation of Mass state?

• Matter cannot be gained or lost in a chemical reaction.
• Matter can only be lost in a chemical reaction.
• Matter can only be gained in a chemical reaction.
• Matter can be gained and lost in a chemical reaction. 

What is the left part of a chemical equation called?
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

What is the right part of a chemical equation called...
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

Is the following equation balanced?...
Al + O₂ --> 2Al₂O₃

• Yes!
• No!

Element or compound?
H₂O

• Element
• Compound

What is the number before a chemical formula called?
Ex: 2H₂ + O₂ --> 2H₂O

• Coefficient
• Subscript
• Atom
• Equation

How many aluminum atoms are in Al₂(SO₄)₃?

• 1
• 2
• 3
• 4

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

• H₃PO₄
• H₂SO₄
• HClO₃
• H₂O

How many atoms are in the neurotransmitter serotonin? The formula for serotonin is C₁₀H₁₂N₂O

• 10
• 20
• 25
• 23

What information could a student determine from only the chemical formula of a protein?

• The color of the protein
• The number of molecules in each sequence of the protein
• The physical arrangement of atoms in the structure of the protein
• The number of atoms of each element in the protein