Chemical Equations Basics

Which of the following reactions is balanced?

• 2CH₄ + O₂ -> CO₂ + H₂O

• CH₄ + 2O₂ -> CO₂ + H₂O

• CH₄ + 2O₂ -> CO₂ + 2H₂O

• None of the chemical equations are balanced.

Tags

NGSS.MS-PS1-5

Balance this equation.
_CF₄ + _Br₂ -- _CBr₄ + _F₂

• 2,1,2,1

• 1,2,2,1

• 1,2,1,2

• 2,2,2,2

Tags

NGSS.MS-PS1-5

The substances listed on the right side of a chemical equation are the

• Yields

• Reactants

• Products

• Precipitates

Tags

NGSS.MS-PS1-5

In chemical reactions, what does the principle of conservation of mass mean?

• Matter is not created or destroyed.

• The total mass of the reactants is greater than the total mass of the products.

• The total mass of the reactants is less than the total mass of the products.

• Matter is not changed.
  

Tags

NGSS.MS-PS1-5

Which is the Law of Conservation of Matter?

• matter cannot be created or destroyed, it only rearranges

• matter can be created but it cannot be destroyed, it never rearranges

• matter can be destroyed but it cannot be created, it usually just rearranges

• matter is an unproven theory created by Hans Geiger

Tags

NGSS.MS-PS1-5

Which number should go in the blank?
2 Na+ _ Cl₂ -> 2 NaCl

• 1

• 2

• 3

• 0

Tags

NGSS.MS-PS1-2

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-PS1-2

NGSS.MS-PS1-5

Which is the Law of Conservation of Matter?

• matter cannot be created or destroyed, it only changes form

• matter can be created but it cannot be destroyed, it never changes form

• matter can be destroyed but it cannot be created, it usually just changes form

• matter is an unproven theory created by Hans Geiger

Tags

NGSS.MS-PS1-5

Identify the Reactants in this equation.

• A

• B

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

How many molecules of KNO₃ are shown?

• 1

• 2

• 3

• 4