Balancing Chemical Reactions Basics

Is the following equation balanced or unbalanced?
Fe + S --> FeS

• balanced
• unbalanced

Tags

NGSS.HS-PS1-7

True or False: When balancing chemical equations the subscripts can change.

• true
• false

Tags

NGSS.HS-PS1-7

Which of the Following Correctly Balances this Equation? 
_H_2+_Cl_2 --> _HCl

• 2H_2 _+ Cl_2 --> 4HCl
• H_2+Cl_2 --> 2HCl
• 3H_2 + 3Cl_2 --> HCl
• H + Cl --> HCl

Tags

NGSS.HS-PS1-7

When balancing equations a ____ can be placed to the left of a formula of a substance to make the equations balanced

• charge
• subscript
• random number
• coefficient

When balancing equations what does
 -->
mean?

• subscript
• equals
• it is just an arrow
• yield

Classify the following chemical reaction:
4P +5O_2 --> P_4O_10

• single replacement
• double replacement
• synthesis
• decomposition

Which of the following is an unbalanced equation?

• CaCO_3 --> CaO + CO_2
• PbO_2 + 2H_2-->2Pb + H_2O
• 2Na+ 2H_2O-->2NaOH + H_2
• CS_2 + 2O_2 --> CO_2 + 2SO_2

Tags

NGSS.HS-PS1-7

Which of the following is an example of synthesis?

• Na + Br_2 --> NaBr
• KClO_3 --> KCl + O_2
• HgO + Cl_2-->HgCl + O_2
• Cl_2 + NaBr --> NaCl + Br_2

Which of the following is evidence of a chemical reaction?

• fizzing
• water changing to ice
• saltwater
• paper being cut in half

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What coefficient should be used to make the following equation balanced?
N_2+O_2--> _NO 

• 1
• 2
• 3
• 4

Tags

NGSS.HS-PS1-7