Answer:
(a) 3:2; (b) 2:1
Explanation:
The Law of Multiple Proportions states that when two elements A and B combine to form two or more compounds, the masses of B that combine with a given mass of A are in the ratios of small whole numbers.
That is, if one compound has a ratio r₁ and the other has a ratio r₂, the ratio of the ratios r is in small whole numbers.
(a) Ammonia and hydrazine.
In ammonia, the mass ratio of H:N is r₁ = 0.2158/1
In hydrazine, the mass ratio of H:N is r₂ = 0.1439/1
The ratio of the ratios is:

(b) Nitrogen oxides
In nitrogen monoxide, the mass ratio of O:N is r₁ = 1.142/1
In dinitrogen monoxide, the mass ratio of O:N is r₂ = 0.571/1
The ratio of the ratios is:

10 hectometers
One hectometer is 100 meters in length already, so 10 is 1000
The enthalpy for the reaction : ΔH = -132
<h3>Further explanation</h3>
Given
Reaction and the enthalpy
Required
the enthalpy
Solution
Hess Law
Reaction 1 reverse :
A + B = G + C ΔH = -277
Reactions 2 and 3 remain the same (unchanged)
C + F = A ΔH = 303
D = B + H ΔH = -158
Add up all the reactions and remove the same compound from two different sides
D + F = G + H ΔH = -132
The answer is <span>ionic aluminum fluoride (</span>AlF3). Note that boiling points of pure solvents are raised in the presence of solutes. The type of solute also affects the boiling point elevation of the solution. Ionic substances tend to raise it more than covalent ones, so sucrose is out of the picture. Next, consider the number of ions the ionic substance produces. The more ions, the greater the BPE. AlF3 dissociates into 4 ions.