$CATEGORY: Science - Khan Academy/3.Metals and Non-metals/3.Metals and Non-metals--Occurence of Metals

//Multiple Choice

What is the first step in the extraction of metals from their ores?  
{  
~Reduction of metal oxide  
~Heating the ore with carbon  
=Crushing the ore  
~Electrolysis of the ore  
}  

In the reduction of metal oxides, what is typically used to reduce the metal oxide to metal?  
{  
~Water  
~Hydrogen  
=Carbon  
~Oxygen  
}  

What is the role of heat in the reduction of metal oxides?  
{  
~It helps in the oxidation of the metal  
=It provides energy for the reduction reaction  
~It decomposes the metal oxide  
~It dissolves the metal  
}  

Which of the following is a common product formed during the reduction of metal oxides by carbon?  
{  
~Carbon monoxide  
=Carbon dioxide  
~Hydrogen  
~Oxygen  
}  

During the reduction of iron ore \((Fe_2O_3\)), which of the following is produced as a byproduct?  
{  
~Hydrogen gas  
=Carbon dioxide  
~Nitrogen gas  
~Water  
}  

What is the main purpose of using carbon in the reduction of metal oxides?  
{  
~To absorb impurities  
~To provide heat for the reaction  
=To act as a reducing agent  
~To form a protective layer on the metal  
}  

Which of the following metals is obtained by reduction of its oxide with hydrogen?  
{  
~Iron  
=Copper  
~Aluminium  
~Zinc  
}  

In the extraction of metals, what happens after the metal oxide is reduced to metal?  
{  
~The metal is immediately purified  
=The metal is allowed to cool and then separated from slag  
~The metal is mixed with impurities  
~The metal is dissolved in acid  
}  

In the reduction of metal oxides, why is carbon used instead of other substances?  
{  
~Carbon is more reactive than the metal oxide  
=Carbon is cheap and readily available  
~Carbon reacts with oxygen to form carbon dioxide, removing oxygen from the metal oxide  
~Carbon is a better conductor of electricity  
}  

What is the reduction reaction that takes place when copper oxide is heated with carbon?  
{  
=CuO + C → Cu + CO2  
~CuO + C → Cu + CO  
~CuO + H2 → Cu + H2O  
~CuO + H2 → Cu + O2  
}  


//True or False

The reduction of copper oxide (CuO) with carbon results in the formation of copper and carbon monoxide. {T}  

Iron can be extracted from its ore (Fe2O3) by reducing it with hydrogen gas. {F}  

In the reduction of zinc oxide (ZnO), zinc is obtained and carbon dioxide is released. {T}  

Aluminium oxide (Al2O3) can be reduced by carbon to produce pure aluminium metal. {F}  

The reduction of metal oxides involves the removal of oxygen from the oxide. {T}  

Copper oxide can be reduced by carbon to produce copper metal and carbon dioxide. {T}  

Zinc oxide (ZnO) is reduced by carbon to form zinc metal and oxygen gas. {F}  

Carbon dioxide is produced when iron oxide (Fe2O3) is reduced with carbon. {T}  

The reduction of metal oxides is a process where the metal gains oxygen. {F}  

In the reduction of copper oxide (CuO), carbon is the reducing agent. {T}  


//Fill in the blanks

The process of extracting metals from their ores by heating the metal oxide with carbon is called __________.  
{  
~Electrolysis  
=Reduction  
~Oxidation  
~Distillation  
}  

In the reduction of copper oxide (CuO), carbon is used to remove __________ from copper oxide.  
{  
~Hydrogen  
=Oxygen  
~Carbon  
~Nitrogen  
}  

The reaction of zinc oxide (ZnO) with carbon produces __________ gas.  
{  
~Carbon monoxide  
=Carbon dioxide  
~Oxygen  
~Nitrogen  
}  

In the extraction of iron from its ore (Fe2O3), __________ is used as a reducing agent.  
{  
~Carbon dioxide  
=Carbon  
~Hydrogen  
~Nitrogen  
}  

The reduction of metal oxides by carbon is usually carried out at __________ temperatures.  
{  
~Low  
~Moderate  
=High  
~Room  
}  

During the reduction of copper oxide (CuO) with carbon, copper is __________ to its pure form.  
{  
~Oxidized  
=Reduced  
~Dissolved  
~Decomposed  
}  

In the reduction of zinc oxide (ZnO), __________ is the product formed along with zinc.  
{  
=Carbon dioxide  
~Oxygen  
~Water  
~Hydrogen  
}  

When copper oxide is heated with carbon, the metal copper is __________ from its oxide.  
{  
~Oxidized  
=Reduced  
~Dissolved  
~Precipitated  
}  

The process of extracting metals like aluminium from their oxides requires __________, which is an energy-intensive method.  
{  
=Electrolysis  
~Reduction by carbon  
~Heating with hydrogen  
~Distillation  
}  

In the reduction of iron ore (Fe2O3), the carbon reacts with oxygen to form __________.  
{  
~Carbon monoxide  
=Carbon dioxide  
~Oxygen  
~Hydrogen  
}  


//Numericals

What mass of iron can be obtained by reducing 10 g of iron oxide (Fe2O3) with carbon? {
    =4.48 g
    ~5.6 g
    ~6.56 g
    ~7.6 g
}

When 5 g of zinc oxide (ZnO) is reduced with carbon, what mass of zinc is obtained? {
    =3.45 g
    ~4.5 g
    ~5.2 g
    ~6.5 g
}

How much copper is obtained when 10 g of copper oxide (CuO) is reduced with carbon? {
    =6.35 g
    ~7.5 g
    ~5.5 g
    ~8.0 g
}

If 8 g of zinc oxide (ZnO) is reduced by carbon, how much carbon dioxide is produced? {
    =5.6 g
    ~4.5 g
    ~6.5 g
    ~8.0 g
}

How much carbon dioxide is produced when 10 g of iron oxide (Fe2O3) is reduced by carbon? {
    =8.96 g
    ~6.56 g
    ~10.5 g
    ~12.5 g
}

When 20 g of copper oxide (CuO) is reduced with carbon, what is the mass of copper obtained? {
    =16.5 g
    ~18.5 g
    ~20.5 g
    ~22.5 g
}

What is the mass of iron produced when 10 g of iron oxide (Fe2O3) is reduced by carbon? {
    =6.56 g
    ~4.48 g
    ~5.6 g
    ~7.5 g
}

If 5 g of zinc oxide (ZnO) is reduced by carbon, how much carbon dioxide will be formed? {
    =2.4 g
    ~3.0 g
    ~3.5 g
    ~4.0 g
}

How much carbon dioxide is produced when 12 g of copper oxide (CuO) is reduced by carbon? {
    =4.8 g
    ~3.2 g
    ~5.5 g
    ~6.0 g
}

What is the mass of copper obtained when 10 g of copper oxide (CuO) is reduced by carbon? {
    =6.35 g
    ~5.35 g
    ~7.5 g
    ~8.5 g
}


//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{  
=Iron -> Reduction by carbon  
=Copper -> Reduction by carbon  
=Aluminum -> Electrolysis  
=Zinc -> Reduction by carbon  
}  


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