Bihar STET Paper 2 Chemistry Mock Test - 8 - Bihar PGT/TGT/PRT MCQ

(a) CO (14e), no unpaired electron, magnetic moment = 0
CO⁺ (13e), One electron is lost from bonding melecular orbital unpaired electron = 1, magnetic moment =
(b)  (15e) Unpaired electron = 1, magnetic moment =
(13e) Unpaired electron = 1, magnetic moment =
(c) Zn, Zn²⁺, unpaired electron = 0
(d) O₂ (16e), unpaired electron = 2, magnetic moment =
, unpaired electron = 1, magnetic moment =

The negative electron gain enthalpy of fluorine is less than that of chlorine. It is due to small size of fluorine atom. As a result, there are strong interelectronic repulsions in the relatively small 2p orbitals of fluorine and thus, the incoming electron does not experience much attraction.

B is an alcohol formed by the attack of Grignard's reagent on acetone. Hence, alcohol must have the skeleton


Also, R is C₇H₁₁ with two degree of unsaturation it must be cyclohexenyl methyl not cyclohexyl methyl.

= 2.53/106   2.59 × 10^-2  5.9 × 10^-2
0.238 × 0.25          = 1.18 × 10^-3

250 ml - 0.238

= 0.955

0.955  0.955 

Vapor density = Molecular weight/2

As both the compounds have same molecular weights, both will have the same vapour density. Hence, gaseous density of both ethanol and dimethyl ether would be same under identical conditions of temperature and pressure. The rest of these three properties; Vapour pressure, boiling point and heat of vaporization will differ as ethanol has hydrogen bonding whereas ether does not.

Covalent solid doesnot conduct electricity in molten and solid state.

H₂O₂ is an oxidizing agent in 1st reaction and Reducing agent in 2nd reaction.

In oxymercuration-demercuration reaction, Markownikoff's addition of H₂O takes place with HO^- added to carbon where more stable carbocation could be formed.

The flow of current in a Daniel cell or any other electrochemical cell is due to the movement of electrons from the anode to the cathode. This happens through an external circuit connecting the two electrodes.

• Electron Transfer: In a Daniel cell, the zinc (Zn) electrode is oxidized to zinc ions (Zn²⁺), releasing two electrons. These electrons then move through the external circuit to the copper (Cu) electrode, reducing the copper ions (Cu²⁺) to copper atoms. However, the transfer of electrons does not occur directly from Zn to Cu²⁺ in the solution. Instead, it happens via the external circuit. Therefore, option A is incorrect.

• Potential Difference: The potential difference between the two electrodes in a Daniel cell is what drives the flow of current. When zinc is oxidized at the anode, it leaves behind electrons, creating a negative charge. At the same time, the reduction of copper ions at the cathode absorbs electrons, creating a positive charge. This difference in charge creates a potential difference or voltage that causes the electrons to flow from the anode to the cathode, generating current. Therefore, option B is correct.

• Salt Bridge: A salt bridge is a device used to complete the circuit in a Daniel cell by allowing the flow of ions between the two half-cells. This maintains the electrical neutrality within the half-cells, enabling the reaction to continue. However, it does not directly facilitate the flow of current, which is driven by the potential difference between the electrodes. Therefore, option C is incorrect.
• Platinum Wire: While a wire, such as one made of platinum, is needed to connect the two electrodes and provide a path for the electrons to move, it is not the presence of the wire itself that allows for the flow of current. Rather, it is the potential difference between the electrodes. Therefore, option D is incorrect.

In conclusion, the flow of current in a Daniel cell is possible if there is a potential difference between the copper and zinc electrodes. This potential difference drives the movement of electrons from the anode to the cathode, generating current.

The enthalpies of fusion for all reactions are always positive because melting of a solid is an endothermic process in which heat is supplied to the reaction Hence the sum of enthalpies of the product is greater than the sum of enthalpies of the reactant.

Ozone is detected by using Hg.

 NH4HS (s)  ⇋ NH3 (g) + H2S (g)
Initial    1                   -               -
At eqm     1-x                 x+0.02     x
Kc = [NH₃][H₂S]   (Since NH4HS is solid, we ignore it.)
1.8×10-4    = (x+0.02)(x)
x2+0.02x-1.8×10-4 = 0
Applying quadratic formula; x = -0.02+√{(0.02)2-4×1.8×10-4}
= 0.033-0.020/2 = 0.0065
Therefore, concn of NH₃ at equilibrium = x+0.020 = 0.0265
concn of H2S at equilibrium = x = 0.0065
So, option b is correct

(i) CaOCI₂ has



Oxidation number = + 6
Oxidation number = - 2
(ii) → (p,u)


(iii) → (q.v)

Vapour pressure is equal to atmospheric pressure ,it means the substance is at boiling point
At boiling point, liquid and Gas are in equilibrium. Therefore dG=0
dG = H - TdS
dG = 0
⇒H = TdS
⇒T = H/dS
⇒ T = 30 103/75 = 400K

Four primary amines are possible with the molecular formula C₄H₁₁N.

Structure with least formal charge on each atom, makes greater contributions. Also, structures with at least one neutral atom is also favoured II and III identical.

• The nature of positive rays produced in a vacuum discharge tube depends upon the nature of the gas-filled.
• The positive rays consist of positive ions obtained by removing one or more electrons from gas molecules.

The correct answer is option c
NO_(g)+Br_2(g)     ⇌NOBr_2(g)
NOBr2_(g)+NO_(g) 2NOBr_(g)[rate determining step]
Rate of the reaction (r)= K[NOBr₂][NO]
Where [NOBR²]=Kc[NO][Br2]
r=K.K_c.[NO][Br²][NO]
r=K’[NO]²[Br₂].
The order of the reaction with respect to
NO(g)=2.
 

x²  +  10^–4 x – 2 × 10^–8 = 0
x = 10^–4
[OH–] = x + 10^–4
= 2 × 10^–4

The way in which students bring their finding to others and apply their understanding to new and unfamiliar circumstances, grows out of excitement for what they have accomplished. Student would be excited to reveal his finding.

Teachers play the most crucial role in moulding the behaviour of learners. This shaping of behaviour is achieved through planning and dedication.

The Primary duties of a teacher include:

• to achieve all-round development of students by guiding the students in their learning process.
• to provide motivation for learning.
• to stimulate learners in order to realize their optimum potential.
• to plan the teaching and learning process to suit the needs of the students.
• to promote learning by providing a conducive environment.
• to encourage learners to become active learners.

​Although imparting knowledge and values into the students are important duties of a teacher. However all round development of students is the most important and vital duty of a teacher.

Thus, the primary duty of the teacher is to help in all round development of the students.

Teachers use different evaluation methods because different subjects require different methods of assessment like science can be assessed by practical exams and languages can be assessed by evaluating verbal ability and fluency.

Activity-based learning as the name suggests actively involves learners in the construction and re-construction of knowledge based on his or her individual experiences. It is known as the learning by doing method. The activity approach takes you a little more time to prepare than a lecture or a demonstration. But the activity approach will not add to your burden. Rather, it will promote and support you by providing a range of appropriate educational material and ideas, and orientation on the creative use of the same. And the rewards for both you and your students will be significant and satisfying.

Key Points

The four steps to practicing activity-based learning are:  

Planning:  It is important to identify the learning objectives that would be achieved through the planned activity.

• Now you need to make a list of and arrange for the various resources that may be required—material, learning resources, volunteers, etc.
• Plan for debriefing/discussion after the activity should also be developed by you. You will also require to have an idea about how will you assess, not only the learners but also the effectiveness of the activity.

Conducting the Activity While conducting the activity, as a facilitator, you may need to work in the following phases:

• Initiate the Activity: Introduce the activity and inform the children about the purpose or objective of the activity, their role in it, the time duration, and evaluation details if any.
• Proceed with the Activity: Once you have initiated, your main role is to ensure that children can meaningfully do what they are expected to do. Remember, encouraging all children are required to keep them motivated and involved.
• End the Activity: This phase is important to consolidate the learnings. This may require that the students reflect on the experiences and derive learnings relevant to the identified objective. If it is not done, sometimes the children are unable to relate the activity to essential learning. The teacher can also conclude by suggesting the linkages of the activity to real-life situations, and further direction. This phase is crucial for establishing links between what children experienced and what they read in their text-book.

Reflecting on the Process: This phase is for the teacher to take her own notes and learnings from the experience of conducting the activity. Thus you must spend some time reflecting on what worked well and what did not, and why? These notes/reflections will help you improve the design, planning, and conducting activity in the future.

Revising: As a result of reflection, the teacher often realizes the benefits and strengths of conducting the activity. An objective analysis of the experience also reveals the scope for improving the same activity for the next time.

Hence, we can conclude that Activity-based learning means learning by doing.

Learning is effective in an environment that is emotionally positive and satisfying to learners. Any learner who is emotionally unstable may not be able to learn anything. The teacher must make the environment conducive for students to study and learn efficiently.
Errors made by the students do not indicate that no learning has taken place. Instead, they are the windows through which a teacher can understand the thought process of the students.
Learning is affected by emotional factors at any stage. Emotions change over time as the child matures, and in response to changing environmental interactions. The kind of learning that takes place at different emotional levels also differs.
Learning involves physical, social and emotional activity also.

The Indian Air Force (IAF) is set to conduct ‘Gagan Shakti-2024’, the nation’s largest air military exercise, involving all Air Force stations. Held every five years, it will commence on April 1, 2024, at Pokhran’s field firing range. Approximately 10,000 airmen will participate, with maneuvers spanning the Western and Northern fronts. The Indian Army is aiding logistical support, ensuring synergy across sectors for operational rail mobilization.

The activity will help the students to gain first-hand experience. This helps in better retention of the concepts.

The students are required to understand the relative positions and relative distances of places. They must know how to use the scale and symbols. Drawing precisely according to the scale is not important.