Answer:
Various limitations of Mendeleev's periodic table are:-
Position of hydrogen - he couldn't assign a correct position to hydrogen as it showed properties of both alkali and halogens .
Position of isotopes - he considered that the properties of elements are a function of their atomic masses. Hence isotopes of a same element couldn't be placed.
In the d-block , elements with lower atomic number were placed before higher atomic number.
Explanation:
1 mol of any gas or mix of gases at STP conditions will have a volume of 22.4 L. Since the problem doesn’t said what are the conditions I will asume that are STP condition and the volume of one mole of the mix will have a volume of 22.4 L.
You may know that density is
D=m/v
In one mole of air I will have 80% of Nitrogen (N2) and 20% oxygen (O2).
So the mass of one mole of air will be
14 x2x0.80+16x2x0.20 = 22.4 g + 6.4 g = 28.8 g
D= 28.8/22.4 = 1.28 g/L
Of course if the temperature is higher the density will be smaller because the volume of one mole will be bigger and viceversa if the temperature decrease. Also if the pressure is different than one atm the volume of a mol will change.
Answer:
combustion is fast and destructive it also involves a lot of movement of the atoms where erosion is a slow process that does not involve a lot of energy
