Explanation:
The given data is as follows.
= 0.042 M,
for 
According to the given situation
acts as a base.The reaction equation will be as follows.

Relation between
and
are as follows.


= 
= 
Also,
Let us take
= x
So, ![K_{b} = \frac{[HP^{-}][OH^{-}]}{P^{2-}}](https://tex.z-dn.net/?f=K_%7Bb%7D%20%3D%20%5Cfrac%7B%5BHP%5E%7B-%7D%5D%5BOH%5E%7B-%7D%5D%7D%7BP%5E%7B2-%7D%7D)
x = 
= 
pOH = - log![[OH^{-}]](https://tex.z-dn.net/?f=%5BOH%5E%7B-%7D%5D)
= - log (
)
= 4.99
As it is known that pH + pOH = 14
so, pH + 4.99 = 14
pH = 9.01
Thus, we can conclude that pH of the solution is 9.01.
Here we have to get the moles of hydrogen (H₂) consumed to form water (H₂O) from 1.57 moles of oxygen (O₂)
In this process 3.14 moles of H₂ will be consumed.
The balanced reaction between oxygen (O₂) and hydrogen (H₂); both of which are in gaseous state to form water, which is liquid in nature can be written as-
2H₂ (g) + O₂ (g) = 2H₂O (l).
Thus form the equation we can see that 1 mole of oxygen reacts with 2 moles of hydrogen to form 2 moles of water.
So, 1.57 moles of oxygen will consume (1.57×2) = 3.14 moles of hydrogen to form water.
Explanation:
For AX type ceramic material, the number of formula per unit cells is as follows.

or, 
where, n' = no. of formula units per cell
= molecular weight of cation = 90.5 g/mol
= molecular weight of anion = 37.3 g/mol
= volume of cubic cell = 3.55
a = edge length of unit cell = 
= Avogadro's number = 
= density = 3.55 
Now, putting the given values into the above formula as follows.

= 
= 0.9
= 1 (approx)
Therefore, we can conclude that out of the given options crystal structure of cesium chloride is possible for this material.
Answer:
The element is Na
Explanation:
Ionization energy is the energy needed to release the last electron from an atom in its ground state to the gaseous state. It is a periodic property that increases as we go through the periods of the periodic table, but decreases if we move in groups. Sodium has thr ionic radius (another periodic property) that is too large, making it easier to release the electron away, since it is too far from the nucleus.