$CATEGORY: Science - Khan Academy/1.Chemical Reactions and Equations/1.Chemical Reactions and Equations--Types of Chemical Reactions

//Multiple Choice

Which of the following is an example of an exothermic reaction?
{
= Burning of magnesium ribbon
~ Heating of iron sulfate
~ Decomposition of silver chloride
~ Electrolysis of water
}

What does "exo" in exothermic reaction mean?
{
~ Internal
= Out or external
~ Cold
~ Heat
}

What is released during an exothermic reaction?
{
= Energy in the form of light and heat
~ Energy in the form of electricity
~ Gases only
~ Water only
}

What does "thermic" in exothermic reaction mean?
{
~ Related to light
= Related to heat
~ Related to sound
~ Related to electricity
}

What is required to start an endothermic reaction?
{
= Heat energy
~ Light energy
~ Sound energy
~ Chemical energy
}

In an exothermic reaction, the total energy released is greater than\:
{
= The energy required to break bonds
~ The energy required to form products
~ The energy required to initiate the reaction
~ None of the above
}

Which chemical equation represents a decomposition reaction?
{
= 2FeSO₄ \= Fe₂O₃ + SO₂ + SO₃
~ 2Mg + O₂ \= 2MgO
~ C + O₂ \= CO₂
~ CaO + H₂O \= Ca(OH)₂
}

What is the general property of combination reactions?
{
~ They are endothermic
= They are exothermic
~ They require energy to break bonds
~ They do not release any energy
}

Which of the following reactions is an example of a combination reaction?
{
= Magnesium ribbon burning in air
~ Heating iron sulfate
~ Decomposition of silver chloride
~ Electrolysis of water
}

In the reaction C + O₂ → CO₂ + Δ , what does Δ indicate?
{
~ Absorption of energy
= Energy is released in the form of heat
~ Energy is required
~ Light energy is produced
}

Which of these reactions requires heat to initiate?
{
~ Magnesium ribbon burning
= Decomposition of iron sulfate
~ Coal burning
~ Calcium oxide reacting with water
}

What happens in a decomposition reaction?
{
~ Multiple products combine to form one product
= One reactant breaks down into multiple products
~ Energy is released
~ Energy is absorbed
}

//True or False

Exothermic reactions absorb heat. {F}

Endothermic reactions require heat to proceed. {T}

The burning of magnesium ribbon is an exothermic reaction. {T}

Decomposition reactions always release energy. {F}

In a combination reaction, multiple reactants combine to form one product. {T}

Magnesium burning in oxygen is a combination reaction. {T}

Exothermic reactions always require heat to start. {F}

In the reaction C + O₂ \= CO₂, energy is released. {T}

Calcium oxide reacting with water is an exothermic reaction. {T}

The decomposition of iron sulphate requires heat to begin. {T}

In endothermic reactions, energy is absorbed from the surroundings. {T}

Decomposition reactions typically break down one reactant into multiple products. {T}

Endothermic reactions release energy as light or heat. {F}


//Fill in the blanks

The reaction of magnesium with oxygen forms __________.
{
~ Magnesium hydroxide
= Magnesium oxide
~ Magnesium sulphate
~ Magnesium chloride
}

In the reaction 2FeSO₄ → Fe₂O₃ + SO₂ + SO₃, heat is required on __________ side.
{
= Reactant
~ Product
~ Both sides
~ Neither side
}

The burning of coal in air results in the formation of __________.
{
~ Magnesium oxide
= Carbon dioxide
~ Calcium hydroxide
~ Iron oxide
}

__________ reactions generally require heat to break bonds.
{
~ Exothermic
= Endothermic
~ Combination
~ Decomposition
}

__________ is an example of a decomposition reaction.
{
~ Burning of magnesium
= Electrolysis of water
~ Burning of coal
~ Formation of calcium hydroxide
}

__________ reactions are characterized by the release of energy.
{
~ Endothermic
= Exothermic
~ Decomposition
~ Synthesis
}

The reaction of calcium oxide with water results in __________.
{
~ Magnesium hydroxide
= Calcium hydroxide
~ Calcium carbonate
~ Calcium sulphate
}

__________ is produced when magnesium burns in oxygen.
{
= Magnesium oxide
~ Magnesium sulphate
~ Magnesium chloride
~ Magnesium hydroxide
}

The burning of magnesium ribbon is an example of a __________ reaction.
{
= Exothermic
~ Endothermic
~ Synthesis
~ Decomposition
}

In the reaction CaO + H₂O \= Ca(OH)₂, energy is __________.
{
~ Absorbed
= Released
~ Not involved
~ Converted to light
}

The reaction of silver chloride with light is an example of __________ reaction.
{
= Endothermic
~ Exothermic
~ Decomposition
~ Combination
}

The reaction of magnesium and oxygen is an example of a __________ reaction.
{
= Combination
~ Decomposition
~ Endothermic
~ Substitution
}

//Numericals



//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{
=Energy Absorbed -> Requires energy to break bonds
=Calcium Oxide + Water -> Forms calcium hydroxide
=Magnesium Ribbon Burning -> Results in the formation of magnesium oxide
=Iron Sulfate Decomposition -> Requires heat to initiate
=Endothermic Reaction -> Energy is absorbed from the surroundings
}


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