Advertisements
Advertisements
Question
When water is added gradually to a white solid X, a hissing sound is heard and a lot of heat is produced forming a product Y. A suspension of Y in water is applied to the walls of a house during white washing. A clear solution of Y is also used for testing carbon dioxide gas in the laboratory.
(a) What could be solid X? Write its chemical formula.
(b) What could be product Y? Write its chemical formula.
(c) What is the common name of the solution of Y which is used for testing carbon dioxide gas?
(d) Write chemical equation of the reaction which takes place on adding water to slid X.
(e) Which characteristic of chemical reactions is illustrated by this example?
Advertisements
Solution
(a) Solid X is calcium oxide, commonly known as quicklime. Its chemical formula is CaO.
(b) Product Y is calcium hydroxide, commonly known as slaked lime. Its chemical formula is Ca(OH)2.
(c) Common name of the solution of Y is "lime water", which is used to test carbon dioxide gas.
(d) CaO (s) + H2O (l)→ Ca(OH)2 (aq) + HEAT
(e) This chemical reaction is characterised by change in temperature because a huge amount of heat is evolved in this reaction, causing rise in temperature of the mixture.
APPEARS IN
RELATED QUESTIONS
Balance the chemical equation.
\[\ce{HNO3 +Ca(OH)2 -> Ca(NO3)2 + H2O}\]
Balance the given equation:
H2O2 
H2O + O2
What is a chemical equation? Explain with the help of an example.
Balance the given chemical equation:
C + CO2 → CO
When hydrogen is passed over copper oxide, copper and steam are formed. Write a balanced equation for this reaction and state which of the chemicals are elements.
Write a balanced chemical equation for the process of photosynthesis giving the physical states of all the substances involved and the conditions of the reaction.
What do you understand by exothermic reactions?
Is Respiration an endothermic reaction or an exothermic reaction?
Balance the following chemical equation:
Balance the following equation .
N2 + O2 → NO
Balance the following equation. Also name the product formed.
`"Na"+ "H"_2 "O" → "NaOH"+ "H"_2`
Balance the following equation. Also name the product formed.
CO2 + C → CO
Write the chemical equation for the following word equation and balance them.
Calcium oxide + Carbon dioxide → Calcium carbonate
What is thermit process?
Give one example in the case where supplying energy [given below] is necessary for a chemical reaction.
Catalyst
Name the following:
A catalyst which increases the rate of a chemical reaction.
Balance the following simple equation:
Al + N2 → AlN
Balance the following simple equation:
Ca + H2O → Ca(OH)2 + H2
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
PbO2 +4HCl → PbCl2 + H2O + Cl2
What are reactants? Explain with the help of example.
