chemical equations

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.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

Identify the number in blue.

• Product

• Reactant

• Coefficient

• Subscript

Tags

NGSS.MS-PS1-1

In what state is this substance?

• solid precipitate

• dissolved in water

• released as a gas

• liquid

Tags

NGSS.MS-PS1-4

How many atoms of nitrogen are in the compound shown above?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-1

What coefficient should go in the blank space to balance the chemical equation? 
2Al  +____  HCl   →    2AlCl₃  +  3H2

• 2
• 4
• 3
• 6

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

What does this symbol Δ above the arrow mean?

• a precipitate is form

• heat is supplied

• a calalyst is needed

• electricity is needed

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Is the following reaction balanced?
NaHCO₃ --> Na₂CO₃ + H₂O + CO₂

• yes
• no

Tags

NGSS.MS-PS1-5

Translate the following chemical equation into a sentence:

Mg (s) + 2HNO₃ (aq) --> Mg(NO₃)₂ (aq) + H₂ (g)

• Magnesium and hydrogen nitrate react to produce magnesium nitrate and hydrogen.

• Solid magnesium and nitric acid react to produce aqueous magnesium nitrate and hydrogen gas.

• Magnesium ribbon and aqueous hydrogen nitrate react to produce a magnesium nitrate precipitate and hydrogen grams.

• Smooth magnesium and aquaceous nitrate acid react to produce aquaceous magnesium nitrate reacts with hydrogen gas.

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2