Quick Review Flashcards - Click to flip and test your knowledge!
Question
Define a 'chemical reaction' in terms of substance transformation.
Answer
A chemical change in which reactants are transformed into one or more new substances called products.
Question
What occurs to the existing bonds of reactant atoms during a chemical reaction?
Answer
The existing bonds are broken, and new bonds are formed to result in products.
Question
Term: Chemical bond
Answer
Definition: The linkage or force acting between two atoms to hold them together as a stable molecule.
Question
How is a chemical reaction represented in a shorthand form?
Answer
A chemical equation.
Question
In a chemical equation, on which side are the 'reactants' written?
Answer
The left-hand side.
Question
What colour change occurs when blue copper $[II]$ nitrate is heated?
Answer
It changes from blue to black (forming copper $[II]$ oxide).
Question
When white lead $[II]$ nitrate is heated, it forms a yellow residue called _____.
Answer
Litharge ($PbO$)
Question
Which gas is evolved when sodium sulphite reacts with dilute sulphuric acid?
Answer
Sulphur dioxide ($SO_2$)
Question
Identify the gas evolved from the reaction of calcium carbonate with dilute hydrochloric acid.
Answer
Carbon dioxide ($CO_2$)
Question
What gas is produced when ammonium chloride is reacted with calcium hydroxide?
Answer
Ammonia ($NH_3$)
Question
Term: Precipitate
Answer
Definition: An insoluble solid formed during a chemical reaction in a solution.
Question
What is the colour and identity of the precipitate formed when lead nitrate reacts with sodium chloride?
Answer
White precipitate of lead chloride ($PbCl_2$).
Question
When copper $[II]$ sulphate reacts with sodium hydroxide, what specific precipitate is formed?
Answer
A pale blue precipitate of copper $[II]$ hydroxide ($Cu(OH)_2$).
Question
A chemical reaction that proceeds with the evolution of heat energy is termed _____.
Answer
Exothermic
Question
A chemical reaction that proceeds with the absorption of heat energy is termed _____.
Answer
Endothermic
Question
In chemical notation, what does the symbol $+\Delta$ represent regarding energy change?
Answer
Evolution of heat (exothermic reaction).
Question
In chemical notation, what does the symbol $-\Delta$ represent regarding energy change?
Answer
Absorption of heat (endothermic reaction).
Question
Is the reaction between nitrogen and hydrogen to form ammonia exothermic or endothermic?
Answer
Exothermic
Question
Is the reaction between nitrogen and oxygen to form nitrogen monoxide exothermic or endothermic?
Answer
Endothermic
Question
A reaction where two or more elements or compounds react to form a single new compound is called a _____ reaction.
Answer
Direct combination (or Synthesis)
Question
Identify the type of reaction represented by the general equation $A + B \rightarrow AB$.
Answer
Direct combination (Synthesis)
Question
A reaction where a single chemical compound breaks down into two or more simpler substances is a _____ reaction.
Answer
Decomposition
Question
Identify the type of reaction represented by the general equation $AB \rightarrow A + B$.
Answer
Decomposition
Question
A reaction where an element or radical replaces another element in a compound is called a _____ reaction.
Answer
Displacement (or Substitution)
Question
Identify the type of reaction represented by the general equation $A + BC \rightarrow AC + B$.
Answer
Displacement
Question
A reaction where two reactants decompose to form two new substances by exchanging radicals is a _____ reaction.
Answer
Double decomposition
Question
Identify the type of reaction represented by the general equation $A^+B^- + C^+D^- \rightarrow A^+D^- + C^+B^-$.
Answer
Double decomposition
Question
Which specific compound is formed when carbon monoxide ($CO$) combines with oxygen ($O_2$)?
Answer
Carbon dioxide ($CO_2$)
Question
What acid is produced when sulphur dioxide ($SO_2$) reacts with water?
Answer
Sulphurous acid ($H_2SO_3$)
Question
What acid is produced when phosphorus pentoxide ($P_2O_5$) reacts with water?
Answer
Phosphoric acid ($H_3PO_4$)
Question
Reaction of basic oxides like $Na_2O$ with water produces _____.
Answer
Sodium hydroxide ($NaOH$)
Question
Identify the soluble salt produced by the direct combination of aluminium and chlorine.
Answer
Aluminium chloride ($AlCl_3$)
Question
Which insoluble salt is formed by the synthesis of iron and sulphur?
Answer
Iron $[II]$ sulphide ($FeS$)
Question
What are the required temperature and pressure conditions for the manufacture of ammonia via the Haber process?
Answer
$450^{\circ}C$ to $500^{\circ}C$ and $200$ to $900$ atmospheres.
Question
What catalyst is used in the synthesis of ammonia from nitrogen and hydrogen?
Answer
Finely divided iron ($Fe$).
Question
How is sulphuric acid ($H_2SO_4$) prepared through direct combination?
Answer
By the dissolution of sulphur trioxide ($SO_3$) in water.
Question
What condition is necessary for moist hydrogen gas to combine with chlorine to form $HCl$?
Answer
Presence of diffused sunlight.
Question
Name the compound formed by combining ammonia vapours with hydrogen chloride gas.
Answer
Ammonium chloride ($NH_4Cl$)
Question
Which basic oxide reacts with carbon dioxide to form limestone ($CaCO_3$)?
Answer
Calcium oxide ($CaO$)
Question
What are the decomposition products of mercury $[II]$ oxide ($HgO$)?
Answer
Mercury ($Hg$) and oxygen ($O_2$).
Question
Which metal hydroxides are 'stable to heat' and do not decompose?
Answer
Hydroxides of potassium ($K$) and sodium ($Na$).
Question
What products are formed when calcium hydroxide is heated?
Answer
Calcium oxide and water (steam).
Question
What products are formed when copper carbonate ($CuCO_3$) undergoes thermal decomposition?
Answer
Copper $[II]$ oxide ($CuO$) and carbon dioxide ($CO_2$).
Question
Thermal decomposition of potassium nitrate ($KNO_3$) yields which two products?
Answer
Potassium nitrite ($KNO_2$) and oxygen ($O_2$).
Question
Which gases are released when lead nitrate is thermally decomposed?
Answer
Nitrogen dioxide ($NO_2$) and oxygen ($O_2$).
Question
Decomposition of silver nitrate ($AgNO_3$) results in the formation of which metallic residue?
Answer
Silver ($Ag$)
Question
What is the physical observation when ammonium dichromate is heated?
Answer
It decomposes violently with flashes of light, leaving a green residue of chromic oxide.
Question
What occurs when blue hydrated copper sulphate is heated strongly?
Answer
It decomposes into copper $[II]$ oxide, sulphur dioxide, and oxygen.
Question
Term: Thermal dissociation
Answer
Definition: A reversible decomposition reaction brought about by the application of heat.
Question
Provide an example of a chemical that undergoes thermal dissociation.
Answer
Ammonium chloride ($NH_4Cl$) or dinitrogen tetroxide ($N_2O_4$).
Question
A decomposition reaction brought about by the passage of an electric current is called _____.
Answer
Electrolytic decomposition
Question
Give an example of a compound that undergoes photochemical decomposition.
Answer
Silver chloride ($AgCl$) or hydrogen peroxide ($H_2O_2$).
Question
Term: Calcination
Answer
Definition: The process of heating concentrated carbonate ore in limited air to convert it to its oxide.
Question
What determines the ability of one metal to displace another from its aqueous solution?
Answer
Its relative position in the electrochemical (reactivity) series.
Question
In a displacement reaction, a _____ electropositive metal displaces a _____ electropositive metal from its solution.
Answer
more; less
Question
Why does Zinc displace Copper from copper $[II]$ sulphate solution?
Answer
Zinc is more electropositive (higher in the reactivity series) than copper.
Question
Which gas is released when active metals like Magnesium react with dilute hydrochloric acid?
Answer
Hydrogen ($H_2$)
Question
Term: Precipitation reaction
Answer
Definition: A double decomposition reaction between two compounds in aqueous state to produce one insoluble compound.
Question
What is the colour of the precipitate formed by the reaction of $FeCl_3$ with $NaOH$?
Answer
Reddish brown ($Iron [III] hydroxide$).
Question
What is the colour of the precipitate formed by the reaction of $FeSO_4$ with $NaOH$?
Answer
Dirty green ($Iron [II] hydroxide$).