A catalyst is a substance that speeds up a chemical reaction.
Answer: yes, Air is a homogeneous mixture of the gaseous substances nitrogen, oxygen, and smaller amounts of other substances. Salt, sugar, and substances dissolve in water to form homogeneous mixtures. A homogeneous mixture in which there is both a solute and solvent present is also a solution
Explanation:
Answer: Volume of the gas at STP is 22.53 L.
Explanation:
Given : Volume = 125 mL (as 1 mL = 0.001 L) = 0.125 L
Temperature = 
Pressure = 
According to the ideal gas equation, the volume of given nitrogen gas is calculated as follows.
PV = nRT
where,
P = pressure
V = volume
n = number of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.

Hence, volume of the gas at STP is 22.53 L.