how to know state of any element in a chemical reaction?
Answers
Explanation:
Answer
The following observations in an activity may suggest that a chemical reaction has taken places.
∙ Change in state
∙ Change in colour
∙Evolution of a gas
∙ Change in temperature
(i) Calcium oxide reacts vigorously with water to produce calcium hydroxide. During this process, a large amount of heat is also evolved, which increases the temperature of the system. This confirms that a chemical reaction has taken place.
CaO(s)+H
2
O(l)→Ca(OH)
2
(aq)
ii) Also, when calcium carbonate is heated, it decomposes to form calcium oxide and carbon dioxide.
Here, evolution of the gas (carbon dioxide) confirms that a chemical reaction has taken place.
CaCO
3
→CaO+CO
2
Answer:
The state of matter of each compound or molecule is indicated in subscript next to the compound by an abbreviation in parentheses. For example, a compound in the gas state would be indicated by (g), solid (s), liquid (l), and aqueous (aq).