Preap Chemical Reactions and Balancing Equations

Consider the general balanced equation for a single replacement reaction shown below:
A + 2BC → AC₂ + B₂
If 5.0moles of A are combined with 4.0moles of BC, what is the maximum number of  moles of B₂ that can form?

• 2.0 moles of B₂
• 4.0 moles of B₂
• 5.0 moles of B₂
• 1.0 moles of B₂

Tags

NGSS.HS-PS1-7

Consider the general balanced equation for a single replacement reaction shown below:
A + 2BC → AC₂ + B₂
The molar mass of B is 1.0grams. If 2.0 moles of A and 2.0 moles of BC are mixed and allowed to react, what theoretical mass of B₂ can form?

• 2.0 grams of B₂
• 1.0 grams of B₂
• 4.0 moles of B₂
• 3.0 moles of B₂

Tags

NGSS.HS-PS1-7

In the chemical reaction
2H₂O  → 2H₂ + O₂

• twice as much H₂ as O₂ will be produced.
• equal amounts of H₂ and O₂ will be produced.
• twice as much O₂ as H₂ will be produced.
• there is no way to know how much of each will be produced.

Tags

NGSS.HS-PS1-7

Ammonia (NH₃) is widely used as a fertilizer and in many household cleaners. How much ammonia is produced when 6 mol of hydrogen gas react with an excess of nitrogen gas in a synthesis reaction?

• 4 mol
• 6 mol
• 3 mol
• 9 mol

Tags

NGSS.HS-PS1-7

The complete combustion of 1.5 moles of methane (CH₄) would require how much O₂?

• 3.0 mol
• 1.5 mol
• 0.75 mol
• 1.0 mol

When nitrogen and oxygen gases react in the cylinder of an automobile engine, nitric oxide gas (NO) is formed. After it escapes into the atmosphere with the other exhaust gases, the nitric oxide then reacts with oxygen to produce nitrogen dioxide gas, one of the precursors of acid rain.
N₂ + O₂  → 2NO
2NO + O₂ → 2NO₂
If 46g of NO₂ are formed, how much nitrogen must have reacted in the engine?

• 14g N₂
• 28g N₂
• 7g N₂
• 46g N₂

Consider the reaction:
CH₄ + 2O₂ → CO₂ + 2H₂O
Select the true statement:

• 4.00 moles of O₂ can react to produce 4.00moles of CO₂.
• 8.00 moles of O₂ can react to produce 144.0 g of H₂O.
• 88.01 g of CO₂ could be produced upon reaction of 64.00 g of O₂.
• 4.00 moles of CH₄ will react with 2.00moles of O₂.

Tags

NGSS.HS-PS1-7

Fe₂O₃ (molar mass = 160. g/mol)
reacts with
CO (molar mass = 28.0 g/mol)
according to the equation
Fe₂O₃(s) + 3CO(g) → 3CO₂(g) + 2Fe(s)
When 400g Fe₂O₃ reacts with excess CO, how many Fe atoms are produced?

• 5 atoms
• 3x10²⁴ atoms
• 6x10²³ atoms
• 1x10²⁴ atoms

Tags

NGSS.HS-PS1-7

Acetylene (C₂H₂) burns in pure oxygen with a very hot flame. The products of this reaction are carbon dioxide and water. How much oxygen is required to react with 52.0 g of acetylene?
?C₂H₂ + ?O₂ → ?CO₂ + ?H₂O

• 160. g
• 32.0 g
• 52.0 g
• 240. g

Write and balance the equation that illustrates the synthesis of water from its elements. How much hydrogen and oxygen would be required to generate 108g of water?

• 12g H₂;
  96g O₂
• 10g H₂;
  64g O₂
• 6g H₂;
  32g O₂
• 2g H₂;
  16g O₂

Tags

NGSS.HS-PS1-7