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

//Multiple Choice

In a double displacement reaction, the ions in the reactants\: {
    ~Combine to form a single molecule
    ~Remain unchanged
    =Exchange positions
    ~Decompose completely
}

The reaction between HCl and NaOH produces\: {
    ~NaOH and HCl
    =NaCl and H₂O
    ~Na₂O and Cl₂
    ~H₂ and NaOH
}

Which product forms as a gas in the volcano experiment? {
    ~Oxygen
    =Carbon dioxide
    ~Hydrogen
    ~Methane
}

Which of the following is insoluble in water? {
    ~Sodium chloride
    ~Sodium sulfate
    =Barium sulfate
    ~Hydrogen sulfide
}

Sodium (Na⁺) ions combine with Cl⁻ ions to form\: {
    ~Hydrogen sulfide
    ~Sodium hydroxide
    =Sodium chloride
    ~Sodium sulfate
}

Which gas escapes from the solution in the reaction between NaHCO₃ and CH₃COOH? {
    ~Hydrogen sulfide
    ~Oxygen
    =Carbon dioxide
    ~Sulfur dioxide
}

What is formed when barium ions react with sulfate ions? {
    ~Sodium sulfate
    ~Barium chloride
    ~Sodium sulfide
    =Barium sulfate
}

What type of reaction involves the formation of a precipitate like barium sulfate? {
    ~Combustion Reaction
    =Precipitation Reaction
    ~Redox Reaction
    ~Synthesis Reaction
}

Why can’t sodium ions exchange positions with hydrogen ions? {
    ~They are oppositely charged
    =They are both positively charged
    ~They are insoluble
    ~They cannot dissociate
}

What happens to barium sulfate when it forms in a reaction? {
    ~It dissolves completely in water
    ~It forms a gas
    =It precipitates out of the solution
    ~It reacts with sodium ions
}

The chemical formula of baking soda is\: {
    =NaHCO₃
    ~CH₃COOH
    ~NaOH
    ~Na₂SO₄
}

In the volcano experiment, what is the primary function of vinegar? {
    ~It reacts to form water
    ~It neutralizes baking soda
    =It provides H⁺ ions for the reaction
    ~It forms NaCl
}

//True or False

Sodium ions are negatively charged. {F}

Barium sulfate forms a precipitate in water. {T}

Carbon dioxide is responsible for the froth in the volcano experiment. {T}

Sodium and hydrogen ions can combine to form a molecule. {F}

Vinegar dissociates into Na⁺ ions and CH₃COO⁻ ions. {F}

H₂S is a gas that escapes from the solution. {T}

Precipitation reactions involve the formation of soluble products. {F}

Positive ions cannot exchange positions with other positive ions. {T}

Sodium acetate (CH₃COONa) is formed in the volcano reaction. {T}

Sodium chloride forms as a precipitate in double displacement reactions. {F}

Double displacement reactions always produce gases. {F}

//Fill in the blanks

The chemical formula of vinegar is ________. {
    ~NaHCO₃
    =CH₃COOH
    ~NaOH
}

In water, NaCl dissociates into Na⁺ ions and ________ ions. {
    ~H+
    ~CH₃COO-
    ~OH-
    =Cl-
}

Barium chloride reacts with sodium sulfate to form barium sulfate and ________. {
    ~Sodium sulfate
    ~Barium chloride
    =Sodium chloride
}

Hydrogen sulfide escapes from the solution as a ________. {
    =gas
    ~liquid
    ~vapour
}

H₂CO₃ further dissociates into water and ________. {
    ~Oxygen
    =Carbon dioxide
    ~Hydrogen
}

Sodium ions are ________ charged. {
    ~Negatively
    =Positively
    ~Neutral
}

The reaction between NaHCO₃ and CH₃COOH is a ________ reaction. {
    ~Precipitation
    ~Combustion
    =Double displacement
}

Precipitation reactions produce an insoluble ________. {
    ~gas
    ~vapour
    =product/precipitate
}

The formula for sodium acetate is ________. {
    ~NaHCO₃
    ~CH₃COOH
    =CH₃COONa
}

The ion that reacts with H⁺ ions to form hydrogen sulfide is ________. {
    ~sodium
    =sulfur
    ~oxygen
}

//Numericals



//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{
=Baking soda -> NaHCO₃ (used in volcano reaction)
=Vinegar -> CH₃COOH (provides H⁺ ions)
=Sodium acetate -> CH₃COONa (a product of the volcano)
=Carbon dioxide -> Escaping gas causing froth
=Barium sulfate -> Forms insoluble compounds like BaSO₄
}


Match the following items from Column A with their correct corresponding options from Column B\:
{
=Dissociation -> Breaking of compounds into ions
=H₂CO₃ -> Dissociates into water and CO₂
=Sodium chloride -> NaCl (forms in double displacement)
=H₂S -> Gas that escapes in reactions
=H⁺ ions -> React with HCO₃⁻ to form H₂CO₃
}


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