A) Ca(OH)2 + CO2 —> CaCO3 + H2O
B) when Ca(OH)2 is reacted with CO2, the CaCO3 produced is a precipitate which turns the solution milky
Molar mass is the mass of a given substance divided by the amount of that substance, measured in g/mol.
Answer : The correct option is, (B) 273.15 K and 1 atm
Explanation :
STP : STP stands for standard temperature and pressure.
STP conditions :
The temperature is,
or
or 
The pressure is,
or 
The volume is 22.4 L for 1 mole of a substance.
Hence, the correct option is, (B) 273.15 K and 1 atm
My guess is b for the question
To determine the amplitude of a transverse wave, measure the highest amount of disturbance from the equilibrium that the wave experiences.