i. Write a balanced chemical equation of Calcium oxide in water:
[tex]CaO (s)+ H _2 O (1) \rightarrow Ca (OH)_2[/tex]
ii. What is the common name for Calcium Oxide?
iii. During production of calcium oxide from limestone, a gas is evolved as a byproduct. Describe the chemical test for the gas and by what method is the gas collected/prepared in the laboratory? Give a reason for your answer.
Answer (2)
Balanced chemical equation: C a O ( s ) + H 2 O ( l ) → C a ( O H ) 2 ( a q )
Common name for Calcium Oxide: Quick lime
Gas evolved: Carbon dioxide ( C O 2 )
Chemical test: C O 2 ( g ) + C a ( O H ) 2 ( a q ) → C a C O 3 ( s ) + H 2 O ( l ) . Limewater turns milky.
Gas collection: Downward displacement of air.
Lab preparation: C a C O 3 ( s ) + 2 H Cl ( a q ) → C a C l 2 ( a q ) + H 2 O ( l ) + C O 2 ( g )
Explanation
Balanced Chemical Equation The balanced chemical equation for the reaction of Calcium oxide with water is:
Chemical Equation C a O ( s ) + H 2 O ( l ) → C a ( O H ) 2 ( a q )
Common Name The common name for Calcium Oxide is Quick lime.
Gas Evolved During the production of calcium oxide from limestone, carbon dioxide ( C O 2 ) gas is evolved as a byproduct.
Chemical Test for Carbon Dioxide The chemical test for carbon dioxide involves bubbling the gas through limewater ( C a ( O H ) 2 ( a q ) ). If carbon dioxide is present, the limewater will turn milky due to the formation of calcium carbonate ( C a C O 3 ). The reaction is:
Reaction Equation C O 2 ( g ) + C a ( O H ) 2 ( a q ) → C a C O 3 ( s ) + H 2 O ( l )
Method of Gas Collection Carbon dioxide is denser than air, so it is collected by downward displacement of air.
Laboratory Preparation of Carbon Dioxide In the laboratory, carbon dioxide is prepared by the reaction of a metal carbonate (e.g., calcium carbonate) with a dilute acid (e.g., hydrochloric acid). The reaction is:
Reaction Equation C a C O 3 ( s ) + 2 H Cl ( a q ) → C a C l 2 ( a q ) + H 2 O ( l ) + C O 2 ( g )
Examples
Understanding chemical reactions and gas properties is crucial in many real-world applications. For example, the production of cement involves the reaction of calcium oxide, and the monitoring of carbon dioxide levels is important in environmental science. Knowing how to identify gases and balance chemical equations helps in various fields, from industrial chemistry to environmental monitoring, ensuring safety and efficiency in processes.
The balanced equation for calcium oxide in water is C a O ( s ) + H 2 O ( l ) → C a ( O H ) 2 ( a q ) . The common name for calcium oxide is Quick Lime, and during its production, carbon dioxide ( C O 2 ) is released, which can be tested using limewater that turns milky. Carbon dioxide is collected via downward displacement of air and can be prepared in the lab by reacting calcium carbonate with hydrochloric acid.
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