Question

classify the sentences based on the chemical reactions they describe. when a clam shell (caco₃) is heated, carbon dioxide (co₂) is given off and a white powder, calcium oxide (cao), forms. nitrogen pentoxide (n₂o₅) is an unstable gas that changes to nitrogen dioxide (no₂) and oxygen (o₂) at room temperature. sodium (na) reacts with chlorine (cl) to give sodium chloride (nacl). zinc (zn) metal reacts with copper sulfate (cu₂so₄) to give zinc sulfate (znso₄) and copper (cu). a strip of magnesium (mg) burns brightly in oxygen (o₂) to form a white powder, magnesium oxide (mgo). on heating iron ore (fe₂o₃) with carbon (c), we get iron (fe) and carbon dioxide (co₂).

Explanation:

Step1: Identify decomposition reactions

Decomposition reactions involve a single - reactant breaking down into two or more products. The reactions "When a clam shell ($CaCO_3$) is heated, carbon dioxide ($CO_2$) is given off and a white powder, calcium oxide ($CaO$), forms" and "Nitrogen pentoxide ($N_2O_5$) is an unstable gas that changes to nitrogen dioxide ($NO_2$) and oxygen ($O_2$) at room temperature" are decomposition reactions as one compound breaks into multiple substances.

Step2: Identify single - displacement reactions

Single - displacement reactions have one element replacing another in a compound. The reaction "Zinc ($Zn$) metal reacts with copper sulfate ($CuSO_4$) to give zinc sulfate ($ZnSO_4$) and copper ($Cu$)" is a single - displacement reaction where zinc replaces copper in copper sulfate.

Step3: Identify combination reactions

Combination reactions involve two or more reactants combining to form a single product. The reaction "Sodium ($Na$) reacts with chlorine ($Cl$) to give sodium chloride ($NaCl$)" and "A strip of magnesium ($Mg$) burns brightly in oxygen ($O_2$) to form a white powder, magnesium oxide ($MgO$)" are combination reactions.

Step4: Identify reduction - oxidation (redox) reactions

The reaction "On heating iron ore ($Fe_2O_3$) with carbon ($C$), we get iron ($Fe$) and carbon dioxide ($CO_2$)" is a redox reaction where iron in iron oxide is reduced and carbon is oxidized.

Answer:

Decomposition reactions:

• When a clam shell ($CaCO_3$) is heated, carbon dioxide ($CO_2$) is given off and a white powder, calcium oxide ($CaO$), forms.
• Nitrogen pentoxide ($N_2O_5$) is an unstable gas that changes to nitrogen dioxide ($NO_2$) and oxygen ($O_2$) at room temperature.

Single - displacement reaction:

• Zinc ($Zn$) metal reacts with copper sulfate ($CuSO_4$) to give zinc sulfate ($ZnSO_4$) and copper ($Cu$).

Combination reactions:

• Sodium ($Na$) reacts with chlorine ($Cl$) to give sodium chloride ($NaCl$).
• A strip of magnesium ($Mg$) burns brightly in oxygen ($O_2$) to form a white powder, magnesium oxide ($MgO$).

Redox reaction:

• On heating iron ore ($Fe_2O_3$) with carbon ($C$), we get iron ($Fe$) and carbon dioxide ($CO_2$).