Answer:
The atomic radius of strontium is larger than magnesium because there are more number of shielding electrones in strontium than magnesium, which causes electron-electron repulsion, that makes the electrons in valance shell to expand. Hence it would decrease the effective nuclear charge.
Particles of gas are more scarcely placed as compared to that of liquid.
the intermolecular forces will be less in gaseous state and hence is less stable
<u>Answer:</u> The freezing point of solution is 2.6°C
<u>Explanation:</u>
To calculate the depression in freezing point, we use the equation:

Or,

where,
= 
Freezing point of pure solution = 5.5°C
i = Vant hoff factor = 1 (For non-electrolytes)
= molal freezing point depression constant = 5.12 K/m = 5.12 °C/m
= Given mass of solute (anthracene) = 7.99 g
= Molar mass of solute (anthracene) = 178.23 g/mol
= Mass of solvent (benzene) = 79 g
Putting values in above equation, we get:

Hence, the freezing point of solution is 2.6°C
Answer:
if ice is added more salt can be dissolved ...........
Explanation:
The reaction equation will be as follows.

Hence, the expression for
is as follows.
![K_{a} = \frac{[H_{2}SO^{-}_{4}][H^{+}]}{[H_{3}AsO_{4}]}](https://tex.z-dn.net/?f=K_%7Ba%7D%20%3D%20%5Cfrac%7B%5BH_%7B2%7DSO%5E%7B-%7D_%7B4%7D%5D%5BH%5E%7B%2B%7D%5D%7D%7B%5BH_%7B3%7DAsO_%7B4%7D%5D%7D)
Let us assume that the concentration of both
and
is x.

x = 0.01118034
This means that the concentration of
is 0.01118034.
Since, we know that the relation between pH and concentration of hydrogen ions is as follows.
pH = ![-log [H^{+}]](https://tex.z-dn.net/?f=-log%20%5BH%5E%7B%2B%7D%5D)
= 
= 1.958
Thus, we can conclude that the pH of a 0.500 M solution of arsenic acid is 1.958.