1) - dissolving ammonium nitrate in water to cool the water.
2) Pressure
3) - a liquid with a high specific heat
4) -Melting ice cubes
5) - the enthalpy is positive
Answer:
Option (d) is correct
N³⁻ > F⁻ > Mg²⁺ > Si⁴⁺
Explanation:
Total electrons for all the species = 10
So these are <u>iso electronic</u> with each other.
We know
Ionic radii ∝ 
- Si⁴⁺ has 14 protons and 10 electrons
- Mg²⁺ has 12 protons and 10 electrons
- N³⁻ has 7 protons and 10 electrons
- F⁻ has 9 protons and 10 electrons
- Iso electronic species with greatest number of protons have small size and vice versa.
- So Si⁺⁴ have smallest size and N³⁻ have largest in size
The reaction is combination of hydrogen molecules and oxygen molecules and form water. So the oxygen and hydrogen required together is equal to the mass of the water formed.
In balancing half-reactions, it is important to know if the medium is basic or acidic. For basic medium, what is added to the reactant side is the hyroxide ion OH- and what is added to the other side is H2O. The answer is the fifth option.