Chemical Reactions

When dry ice (solid carbon dioxide) sublimes it goes directly from a solid to a gas. What type of change is occurring? 

• Chemical change
• Physical change
• None of the above 

Tags

NGSS.MS-PS1-4

How many oxygen atoms are present in the following? 
4Ca(OH)₂

• 4
• 6
• 8
• 1

Tags

NGSS.MS-PS1-1

Why must we balance chemical equations? 

• Our teacher said so
• to abide by the law of conservation of energy
• to abide by the law of conservation of mass

Tags

NGSS.MS-PS1-5

What is changed in a chemical reaction like this one? 
NaOH + HCl   →  NaCl + H₂O

• the number of atoms is changed
• molecules and compounds are changed 
• atoms are changed
• elements are changed 

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

 Fill in the blank to balance the chemical equation. 
2KI  +  ____Cl₂ →  2KCl  +  I₂

• 1
• 2
• 3
• 4

Tags

NGSS.MS-PS1-5

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. 

Tags

NGSS.MS-PS1-5

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 

Tags

NGSS.MS-PS1-5

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

• Yes!
• No!

Tags

NGSS.MS-PS1-5

Two Reactants and One Product

• Decomposition
• Combination
• Combustion
• Single Replacement

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2