Chemical Calculations

In a chemical equation, on what side of the arrow are the reactants?

• left
• right 

In a chemical equation, on what side of the arrow are the products? 

• left 
• right 

True or False?  During a chemical reaction a new substance (or substances) is produced.  

• true 
• false 

Count the total number of atoms in the chemical formula:
5H₂O₂

• 5
• 8
• 12
• 20

Tags

NGSS.MS-PS1-1

Identify the total number of molecules in the chemical formula:
6CH₄

• 6
• 10
• 24
• 30

Tags

NGSS.MS-PS1-1

Which of the following can be changed to balance a chemical equation? 

• products 
• element symbols 
• coefficients 
• subscripts 

Tags

NGSS.HS-PS1-7

A chemical equation is balanced when the number of each type of __________ is the same on both sides of the yield sign.

• compound
• molecule 
• formula
• atom 

Tags

NGSS.HS-PS1-7

Which of the following equations is balanced?

• 2H₂ + O₂ ---> H₂O
• H₂ + 2O₂ ---> 2H₂O
• H₂ + O₂ ---> H₂O
• 2H₂ + O₂ ---> 2H₂O

Tags

NGSS.HS-PS1-7

What does the arrow in a chemical equation mean? 

• matches
• yields
• equals 
• mixes 

Which of the following describes the law of conservation of mass?

• Reactants + Products = 100%
• Matter (mass) cannot be  created or destroyed in ordinary chemical and physical changes, but it can change form
• Mass of products does not equal mass of reactants
• Matter (mass) can be created or destroyed in certain chemical reactions.

Tags

NGSS.HS-PS1-7