A solution reacts with crushed-egg shells to give a gas that turns lime-water milky. The solution contains
(a) NaCl
(b) HCl
(c) LiCl
(d) KCl

AcademicChemistryNCERTClass 10

Correct Answer: (b) HCl

Explanation: The eggshell contains calcium carbonate, which on reaction with HCl liberates CO2 gas which turn lime water to milky.

CaCO3 + 2HCl → CaCl2 + H2O + CO2

The gas thus formed is an effervescent carbon dioxide gas when calcium carbonate reacts with hydrochloric acid. 

[Extra information: pH stands for "power of hydrogen".The "H" is capitalized because it is the hydrogen element symbol. 
Acidic and basic are two extremes that describe a chemical property chemical. The pH scale measures how acidic or basic a substance is. 
  • The pH scale ranges from 0 to 14.
  • A pH less than 7 is acidic in nature.
  • A pH of 7 is neutral.
  • A pH greater than 7 is basic in nature.
pH decreases with an increase in temperature. This does not mean that the water becomes more acidic at higher temperatures. A solution is considered acidic if there is an excess of hydrogen ions (H) over hydroxide ions (OH-).
(Refer to image for better understanding)
Updated on 10-Oct-2022 12:46:40