Bihar STET Paper 2 Chemistry Mock Test - 10 - Bihar PGT/TGT/PRT MCQ

Cu²⁺  + 4NH₃ → [Cu (NH₃)₄]²⁺ (blue)

Structure (a) = structure (c) and, structure (b) = structure (d)

For C₃H₈ : 3C + 4H₂ → C₃H₈ ; ∆H₁
For C₃H₈ : 2C + 3H₂ → C₂H₆ ; ∆H₂
∆H₁ = -[2(C-C)+8(C-H)]+[3C_s→g+4(H-H)]     -(I)
∆H₂ = -[1(C-C)+6(C-H)]+[2C_s→g+3(H-H)]     -(2)
Let bond energy of C-C be x kcal and bond energy of C-H be y  kcal.
From eqn I and 2
 ∆H₁ = -[2x+8y]+[3×172+4×104]     -(3)
∆H₂ = -[x+6y]+[2×172+3×104]     -(4)
Also given, C+O₂ → CO₂; ∆H = -94.0 kcal     -(5)
H₂ + ½ O2 → H₂O ; ∆H = -68.0 kcal      -(6)
C₂H₆ + 7/2 O₂ → 2CO₂ + 3H₂O ; ∆H = -372 kcal     -(7)
C₃H₈ + 5O₂  → 3CO₂ + 4H₂O ; ∆H = -530 kcal-(8)
By inspection method,2 × (5) + 3 × (6) - (7) gives
2C + 3H₂ → C₂H₆ ; ∆H₂ = -20 kcal
And  3×(5) + 4×(6) -(8)
3C + 4H₂ → C₃H₈ ; ∆H₃ = -20 kcal 
By eqn. (3), (4), (9) and (10)
x+6y = 676
2x+8y = 956
x = 82 kcal and y = 99 kcal

In elimination reaction of alkyl halide major product is obtained according to Saytzeff’s rule, which states that when two alkenes may be formed, the alkene which is most substituted one predominates.

4 aromatic isomers are possible.

—CHO para to electron withdrawing —NO₂ group is better hydride (H^-) acceptor.

Chemical Reaction take place between adsorbate and adsorbent in chemisorptions. Therefore it is specific in nature.

Cerium, a rare earth metal, was initially placed in the 'rare earths' group in Mendeleev's Periodic Table. Mendeleev organized elements into groups based on their similar chemical properties, and cerium was grouped with other rare earth elements due to its similar behavior.

The correct answer is option C
Demulsification is the breaking of a crude oil emulsion into oil and water phases. 
Demulsification is used to separate various mixtures like water in oil and oil in water etc.
It completely separates the constituent liquids and hence is the reverse of emulsification.

Conjugate acid of a base is formed by adding H⁺ to it
NH₂^- + H⁺ → NH₃
 

(i) OSF₂ 

sp³-hybridised S -atom (Ip - bp) repulsion, trigonal pyramidal
(ii)→ (s)
(ii) O₂SF₂

 
sp³-hybridised s-atom tetrahedral
(ii) → (P)
(iii) XeF₄

sp³d²-hybridised Xe-atom.
Two lone pairs, square planar (iii) → (r)

sp³-hybridised Cl atom, tetrahedral.
(iv) → (p)

sp³d-hybridised I, three lone pairs at equatorial position linear,
(v) → (q)

Physical force of attraction between watt man filter paper (stationary phase) and adsorbent (mobile phase).

Activity-based learning is a ‘learner-centred’ approach in the teaching-learning process. In this approach, the ‘learner’ or ‘child’ and not the ‘teacher’ is the main focus of the educational program. It emphasizes ‘learning’ rather than ‘teaching’.

• Activity-based learning integrates multiple methods of teaching like Demonstration, Role-play, Brainstorming, Project method, Debate, etc.
• Activity-based learning brings the real issues and problems from day-to-day life in classroom settings.
• It provide provides opportunities to apply multiple senses.
• It includes all objects, events, natural phenomena and social surroundings in the teaching-learning process.
• It clarifies abstract concepts, develops concrete thinking and brings reality in real settings.
• During activity-based learning, the learners use his/her multiple senses to understand the concepts and enhance learning.
• It arouses the child’s interests, abilities, and needs during the learning process.

Hence, we conclude that all the above points are the advantages of the activity-based learning.

The Right Of Children To Free And Compulsory Education Act (RCFCE Act - 2009) is briefly known as the Right To Education Act (RTE - 2009). 

• Its main aim is to provide quality elementary education to all children.
• It enforces Education as a Fundamental Right (Article 21).

​Key Points

• RTE act aims to provide primary education to all children aged 6 to 14 years from class 1st to class 8th.
• Non enrolled/drop-out children be admitted to an age-appropriate class after a period of Special Training.
• No child shall be failed or expelled from school up to class VIII (corresponds to the age group 6-14) under the no-detention policy.
• It emphasized banning corporal punishment, continuous and comprehensive evaluation, making schools and classrooms truly inclusive, and so on. 
• The role of a teacher to conduct the teaching-learning activities in such a way that it helps the child to be free of fear, trauma, and anxiety and helping the child to express views freely.
• The teacher should demonstrate gender equality in the classroom to remove the gender stereotypes among children and to provide equal opportunities to all irrespective of their gender.
  • The teacher shouldn't follow gender biases like Girls can perform well in dance, music, and arts while boys are generally good in science and mathematics.
• The teacher should follow a child-centred approach to meet the needs and learning goals of learners.
• When the child-centred approach is used in the teaching-learning process, then the child participation will automatically increase as they will take interest in learning.

So, one of the important roles of the teacher according to the RTE is to demonstrate Gender Equality.

Activity-based learning refers to learning through hands-on experience to develop an understanding of the environment around us. An activity is an action performed by the students to understand their environment and the environmental processes. 

Key Points

•  Activity-based learning is a form of Learner-centered approach. It stimulates curiosity and independent thinking, develops problem-solving skills, promotes planning and execution of projects, and develops self-learning involving the acquisition of knowledge through observation of phenomena, and creative thinking abilities.
• Tuition -Centric approach - This approach does not exist.
• Teacher-Centric approach - It emphasizes the importance of a teacher and ignores the active involvement of the learner in the teaching-learning process.
• Subject-Centric approach - It focuses on the subject matter and acquiring the subject knowledge through textbooks and resources available to be a master in the subject rather than the development of the child.

Hence, option 2 is the correct solution.

Important Points 

• In a learner-centered approach, the Learner is at the center of all activities and the teacher plays the role of a facilitator of the learning process and an organizer of the learning situation.
• The learner brings with him/her previous knowledge and experiences which influence the classroom learning process.
• In this approach, the focus is given on developmental stages, maturity, learning strategies, prior knowledge and experiences, interests, social context, and culture of the learner.
• The teacher must understand the learner and their learning styles to know in detail the characteristics of each and every learner in our classroom.       

The overall performance of the teacher needs to be assessed for evaluating a teacher's performance. It is not possible to evaluate it at once. Comprehensive view of teacher during the whole session is must for evaluating her performance.

An Se-young of South Korea won the gold medal in the women's singles event at the 2023 World Badminton Championships, defeating Carolina Marín of Spain in the final, 21-12, 21-10. An Se-young, aged 21, became the first woman from South Korea to win the world singles title. She had a dominant tournament, winning all of her matches in straight games, including victories over Olympic champion Chen Yufei and two-time world champion Akane Yamaguchi.

Sunita's experiences have been used to give children a sense of Earth's gravity. Children are made to understand about the pull of Earth.

A, B and D are the correct options because we can write only because of friction between the tip of the pen and the paper. We can walk because of the friction between our feet and the ground. We are able to stop a moving vehicle by applying brakes because of friction.

The basic objective of teaching EVS to students at the primary stage is to link the classroom teaching with real life. Showing a ticket to the students can help them to know about what constitutes the railway ticket in reality. The students will be able to observe the ticket, and understand in a better way using practical knowledge. The observation skill of students will also be enhanced.

Let AB be the kite and AC be the level ground
So that BC - AC.
At that point, ∠BAC = 60°and BC = 75m. Let AB = x meters.
Presently AB/BC = coses60° = 2/ √3
=> x/75 = 2/√3 => x = 150/√3 = 150 * √3/3 = 50 √3m.
∴ Length of the string = 50 √3m.