Chemistry Test

Which of the following shows the correct way to balance the chemical equation?
Fe + O₂ -> Fe₂O₃

• 4Fe + 3O₂ -> 2Fe₂O₃
• 2 Fe + 3O₂ -> Fe₂O₆
• 4 Fe + O₆ -> 2Fe₂O₃
• None of the options are correctly balanced.

Tags

NGSS.HS-PS1-7

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.HS-PS1-7

Balance this equation...
HgO --> Hg + O₂

• It is balanced 
• 2HgO --> Hg + O₂
• 2HgO --> 2Hg + O₂
• I don't know...Oh well!

Tags

NGSS.HS-PS1-7

How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl₂ + H₂

• 1
• 2
• 3
• 4

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.HS-PS1-7

Which coefficients balance this equation:
NH₃  +  O₂ ---->   NO  + H₂O

• 2,3,5,6
• 5,5,4,6
• 4,6,4,5
• 4,5,4,6

Tags

NGSS.HS-PS1-7

Balance this equation.
_CH₄ + _O₂ --> _CO₂ + _H₂O

• 1,2,1,1
• 2,1,2,1
• 1,2,1,2
• 0,2,0,2

Tags

NGSS.HS-PS1-7

Balance this equation
_Al +_HCl --> _H₂ +_AlCl₃

• 2, 6, 3, 2
• it is already balanced
• 4, 12, 3, 4
• 2, 1, 4, 5

Tags

NGSS.HS-PS1-7

Balance this equation.
_SnO₂ +_H₂-->_Sn +_H₂O

• 1,1,2,1
• 1,2,1,1
• 1,2,1,2
• 1,2,2,1

Tags

NGSS.HS-PS1-7

How did Mendeleev arrange the elements?

• alphabetical 
• density
• melting point
• atomic mass

Tags

NGSS.HS-PS1-1