UrbanPro

Take Class 11 Tuition from the Best Tutors

  • Affordable fees
  • 1-1 or Group class
  • Flexible Timings
  • Verified Tutors

Search in

Comment on each of the following observations:

(a) The mobilities of the alkali metal ions in aqueous solution are Li+ < Na+ < K+ < Rb+ < Cs+

(b) Lithium is the only alkali metal to form a nitride directly.

(c) (where M = Ca, Sr or Ba) is nearly constant.

Asked by Last Modified  

Follow 2
Answer

Please enter your answer

(a) On moving down the alkali group, the ionic and atomic sizes of the metals increase. The given alkali metal ions can be arranged in the increasing order of their ionic sizes as: Li+ + + + + Smaller the size of an ion, the more highly is it hydrated. Since Li+ is the smallest, it gets heavily hydrated...
read more

(a) On moving down the alkali group, the ionic and atomic sizes of the metals increase. The given alkali metal ions can be arranged in the increasing order of their ionic sizes as:

Li+ + + + +

Smaller the size of an ion, the more highly is it hydrated. Since Li+ is the smallest, it gets heavily hydrated in an aqueous solution. On the other hand, Cs+ is the largest and so it is the least hydrated. The given alkali metal ions can be arranged in the decreasing order of their hydrations as:

Li+ > Na+ > K+ > Rb+ > Cs+

Greater the mass of a hydrated ion, the lower is its ionic mobility. Therefore, hydrated Li+ is the least mobile and hydrated Cs+ is the most mobile. Thus, the given alkali metal ions can be arranged in the increasing order of their mobilities as:

Li+ + + + +

(b) Unlike the other elements of group 1, Li reacts directly with nitrogen to form lithium nitride. This is because Li+ is very small in size and so its size is the most compatible with the N3– ion. Hence, the lattice energy released is very high. This energy also overcomes the high amount of energy required for the formation of the N3–ion.

(c) Electrode potential (E°) of any M2+/M electrode depends upon three factors:

(i) Ionisation enthalpy

(ii) Enthalpy of hydration

(iii) Enthalpy of vaporisation

The combined effect of these factors is approximately the same for Ca, Sr, and Ba. Hence, their electrode potentials are nearly constant.

read less
Comments

Tutor

a) We know, smaller the size, higher is the hydration energy. Because a small ion can move faster.The mobility of the alkali metal ions in aqueous solution are :Li+ < Na+ < K+ < Rb+ <Cs+Due to smaller the size of the ion, it is more highly hydrated and greater the hydration of the ion; lower...
read more

a) We know, smaller the size, higher is the hydration energy. Because a small ion can move faster.
The mobility of the alkali metal ions in aqueous solution are :
Li+ < Na+ < K+ < Rb+ <Cs+
Due to smaller the size of the ion, it is more highly hydrated and greater the hydration of the ion; lower is its ionic mobility. Since the extent of hydration decreases in order.
Li+ >Na+ >K+ > Rb+> Cs+
Therefore , ionic mobility increases in the reverse order.
e.g., Li+ < Na+ < K+ < Rb+ < Cs+

(b) because of its smaller in size and diagonal relationship with Mg form Nitride directly.
6Li + N2 ---->2Li3N

(c) E°for M2+ +2e--->M
where M = Ca, Sr, Ba is almost same because, E°of any M2+/M electrode depends upon there factors :(i) enthalpy of vaporization (ii) Ionization enthalpy (iii) enthalpy of hydration.since, the combined effect of these factors is almost the same for Ca,Sr and Ba, therefore, their electrode potential are nearly constant.

read less
Comments

Related Questions

Which of the alkali metal is having least melting point?

(a) Na (b) K (c) Rb (d) Cs

Atomic size increases as we move down the alkali group. As a result, the binding energies of their atoms in the crystal lattice decrease. Also, the strength of metallic bonds decreases on moving down a...
Reap
0 0
5
Find the oxidation state of sodium in Na2O2.
Let the oxidation state of Na be x. The oxidation state of oxygen, in case of peroxides, is –1. Therefore, Therefore, the oxidation sate of sodium is +1.
Saddam
0 0
5

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Recommended Articles

Quality education does not only help children to get a successful career and life, but it also hugely contributes to society. The formal education of every child starts from school. Although there are numerous schools, parents find it challenging to choose the right one that would fit their child. It is difficult for them...

Read full article >

Appearing for exams could be stressful for students. Even though they might have prepared well, they could suffer from anxiety, tension etc. These are not good for their health and mind. However, following a few exam preparation tips can save them from all these and help them to score good marks. Let’s find out all...

Read full article >

E-learning is not just about delivering lessons online. It has a much broader scope that goes beyond manual paper or PowerPoint Presentations. To understand the reach of E-learning and how the whole process works in developing the Educational system, we will discuss a few points here. Let us find out how this new learning...

Read full article >

Once over with the tenth board exams, a heavy percentage of students remain confused between the three academic streams they have to choose from - science, arts or commerce. Some are confident enough to take a call on this much in advance. But there is no worry if as a student you take time to make choice between - science,...

Read full article >

Looking for Class 11 Tuition ?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you
X

Looking for Class 11 Tuition Classes?

The best tutors for Class 11 Tuition Classes are on UrbanPro

  • Select the best Tutor
  • Book & Attend a Free Demo
  • Pay and start Learning

Take Class 11 Tuition with the Best Tutors

The best Tutors for Class 11 Tuition Classes are on UrbanPro

This website uses cookies

We use cookies to improve user experience. Choose what cookies you allow us to use. You can read more about our Cookie Policy in our Privacy Policy

Accept All
Decline All

UrbanPro.com is India's largest network of most trusted tutors and institutes. Over 55 lakh students rely on UrbanPro.com, to fulfill their learning requirements across 1,000+ categories. Using UrbanPro.com, parents, and students can compare multiple Tutors and Institutes and choose the one that best suits their requirements. More than 7.5 lakh verified Tutors and Institutes are helping millions of students every day and growing their tutoring business on UrbanPro.com. Whether you are looking for a tutor to learn mathematics, a German language trainer to brush up your German language skills or an institute to upgrade your IT skills, we have got the best selection of Tutors and Training Institutes for you. Read more