Review Chemical Reactions

Multiple Choice

A rearrangement of atoms from a set of subtstances to form a new one:

• Chemical equation

• Change of state

• Chemical reaction

• Physical change

Multiple Choice

Which of the following is a chemical reaction?

• Ice cream melting

• Water boiling

• Glass breaking

• Antacid in water

Multiple Choice

Which of the following is NOT a chemical reaction:

• Precipitate forming

• Rusting

• Cutting potatoes

• Rotten banana

Multiple Choice

Is it a chemical or physical change?

• Chemical

• Physical

Multiple Choice

An example of decomposition reaction is:

• 2 NaHCO₃ → Na₂CO₃ + H₂O + CO₂

• 3 BaCl₂ + Al₂(SO₄)₃ → 3 BaSO₄ + 2 AlCl₃

• Zn + 2 AgCl → ZnCl₂ + 2 Ag

• 8 H₂S + 8 Cl₂ → S₈ + 16 HCl

Multiple Choice

Type of reaction: (NH₄)₂Cr₂O₇ --> N₂ + Cr₂O₃ + 4H₂O

• Synthesis

• Decomposition

• Single replacement

• Double replacement

Multiple Choice

Type of reaction: 2Al + 6HCl --> 2AlCl₃ +3H₂

• Synthesis

• Decomposition

• Single replacement

• Double replacement

Multiple Choice

Type of reaction: 2Fe + O₂ + 2H₂O --> 2Fe(OH)₂

• Synthesis

• Decomposition

• Single replacement

• Double replacement

Multiple Choice

Type of reaction: 2BF₃ + 3H₂O --> B₂O₃ + 6HF

• Synthesis

• Decomposition

• Single replacement

• Double replacement

Multiple Choice

In a combustion reaction an element or compound reacts with:

• Oxygen

• Hydrogen

• Water

• CO2

Multiple Choice

Write the coefficients to balance the equation: ___ AgBr + ___ AlPO₄ --> _{____}Ag₃PO₄ + ___ AlBr₃

• 1, 3, 1, 3

• 3, 1, 1, 1

• 3, 1, 1, 3

• 2, 3, 2, 3

Multiple Choice

Write the coefficients to balance the equation: ___ Fe + ___ AgNO₃ --> ___ Fe(NO₃)₂ + ___ Ag

• 1, 3, 1, 3

• 2, 2, 1, 2

• 1, 6, 1, 6

• 1, 2, 1, 2

Multiple Choice

A substance that lowers the reaction rate

• Inhibitor

• Catalyst

• Accelerator

• Temperature

Multiple Choice

Write the coefficients to balance the equation: PCl₅ +AsF₃ -->__PF₅ + __AsCl₃

• 1, 3, 1, 3

• 3, 5, 3, 5

• 2, 1, 3, 1

• 2, 1, 2, 1

Multiple Choice

Chemical reaction that releases energy in the form of heat

• Exothermic

• Endothermic

• Precipitation

• Redox

Multiple Choice

Write the coefficients to balance the equation: ___ H₂ + ___ O₂ --> ___ H₂O

• 2,1,2

• 2, 2, 1

• 1,1,2

• 1, 2, 1

Multiple Choice

A catalyst is:

• A substance that prevents a chemical reaction to occur

• A substance that increases the reaction rate

• A substance that decreases the reaction rate

• A substance that oxidizes in a chemical reaction

Multiple Choice

In Zn(s)+2HCl(aq)→ZnCl2​(aq)+H2​(g)

• Zinc oxidizes and gains electrons

• Zinc reduces and gains electrons

• Zinc oxidizes and loses electrons

• Zinc reduces and loses electrons

Multiple Choice

The oxidation number of oxygen is always

• +2

• +6

• -2

• -1

Multiple Choice

The overall net charge of a stable compound is always

• Negative

• Positive

• 0

• +/- 1

Multiple Choice

The oxidation number of metals is always

• Negative

• Positive

• 0

• The number of the family

Multiple Choice

The oxidation number of Mn in KMnO4 is

• +5

• +2

• +7

• +6

Multiple Choice

In Fe + O2 -> FeO, oxygen

• Oxidizes

• Reduces

• Increases its oxidation number

• Doesn't oxidize nor reduce

Multiple Choice

Device capable of generating electrical energy from chemical reactions

• Electrochemical cell

• Galvanization

• Electrolysis

• Metal extraction

Multiple Choice

In Fe2(SO4)3 the oxidation number of Fe is

• +3

• +2

• +4

• +1

Multiple Choice

In 2C +O₂ → 2CO

• Carbon gains electrons

• Oxygen loses electrons

• Carbon reduces and oxygen oxidizes

• Carbon oxidizes and oxygen reduces

Multiple Choice

In a redox reaction the species that gains electrons

• Oxidizes

• Reduces

• Increases its oxidation number

Multiple Choice

The cathode is the electrode in which ____________ happens:

• Oxidation

• Reduction

• Precipitation

• Extraction