Bihar STET Paper 2 Chemistry Mock Test - 6 - Bihar PGT/TGT/PRT MCQ

Thermal stability ∝ bond dissociation energy 
(where, E = group 16 elements)
On moving down the group, bond dissociation energy decreases due to increase in bond length. Thus, the order of bond dissociation energy or thermal stability is 
H₂O > H₂S > H₂Se > H₂Te > H₂PO

pH changes from 0 to 7

∴ [H⁺] changes from 1 to 10^-7 M

Accordingly E_red. Decrease by 0.059 log 10^-7 i.e 0.059 x (-7) = -0.41volt

The substance which forms the colloidal solution in water is starch. A colloidal solution is a solution in which the colloid mixes uniformly. All colloids have a Tyndall Effect, which is not exhibited by glucose. Starch is a colloid and thus when mixed with water can form the colloidal solution.

Volume decreased

i.e p increased

no.of moles reactant more

• Oxidation Numbers of Halogens: The halogens (Fluorine, Chlorine, Bromine, Iodine, and Astatine) are a group in the periodic table. They are known for their high electronegativity and hence, when they combine with almost all other elements, they tend to have an oxidation number of -1 as they gain one electron to achieve a stable electronic configuration.
• Exception in the case of Oxygen: However, oxygen is more electronegative than all halogens except fluorine. So, when halogens (chlorine, bromine, and iodine) combine with oxygen, they tend to lose electrons to oxygen and hence, they show positive oxidation states.
• Conclusion: Therefore, when chlorine, bromine, and iodine are combined with oxygen, they have an oxidation number of +1 or any positive number (depending on the number of oxygen atoms they are combined with). Hence, the correct answer is C: +1 or any positive number.

Na₂[Fe(CN)₅NO] is Sodium nitroprusside.

 XeF₂-sp³d hybridised Xe
Three lone pairs on equatorial positions to minimise repulsion; two F-atom at axial position. Thus, it is linear.

(a) TeF₂,Te₅₀ - Six electrons in valence shell

(b)   hybridised l- atom with three lone pairs at equatorial positions to minimise repulsion thus, linear.

(c) SoCI₃ - sp³-hybridised pyramidal Sb-one lone pair on Sb.
(d) BaCI₂ - ionic .

K₂O + H₂O → KOH

F, O and N are electronegative elements. Thus, HF molecules are associated by intermolecules H-bonding giving it a liquid state and thus highest boiling point out of HF, HCl.HBr and HI.
Similarly, H₂O has highest boiling point, and NH₃ has highest boiling point.

Rate constant is also known as velocity constant.

Hydrogen has some properties, resembling with IA group elements (alkali metals) and rest resembling with halogens (VII A group elements). Tendency to gain one electron is the property of halogens. Hence, hydrogen resembles with halogens in this respect.

The presence of particulate matter in polluted air catalyses the oxidation of sulphur dioxide to sulphur trioxide. Oxides of Nitrogen: Di-nitrogen and di-oxygen are the main constituents of air. These gases do not react with each other at a normal temperature.

The elements of "s" and "p" blocks except "d" group elements are called as representative elements. Their outer shells are not completely filled with electrons. The elements get the nearest inert gas configuration by losing or gaining or sharing of electrons. 

Multidentate ligand always act as chelating Ligand

Number of atoms = number of moles x N_A x atomicity

= 0.1 x 6.02 x 10²³ x 3

= 1.806 x 10²³

ΔTb/Kb = ΔTf/Kf
0.186/18.6 = ΔTb/0.512
ΔTb = 0.1x0.512
= 0.0512.
Boiling point = boiling point (of water) + ΔTb
=> 100 + 0.0512
= 100.0512

• Sodium carbonate, Na₂CO₃, (washing soda) is the water-soluble sodium salt of carbonic acid, well-known domestically for its everyday use as a water softener.
• Pure sodium carbonate is a white, odorless powder that is hygroscopic (absorbs moisture from the air).
• It has a strongly alkaline taste and forms a moderately basic solution in water.

This alkaline earth hydride is a colourless solid that is insoluble in solvents that do not decompose it. Unlike the ionically bonded hydrides of the heavier Group 2 elements, beryllium hydride is covalently bonded (three-center two-electron bond).

The rate of development of an individual child is different from that of another child. This principle is known as the ‘principle of individual differences’. For instance, some children may learn to walk in 8 months, while some may take more than a year to start walking. 

It is important for teachers to know variables such as physical characteristics, intelligence, perception, gender, ability, learning styles, which are individual differences of learners. An effective and productive learning-teaching process can be planned by considering these individual differences of students.

Teaching-learning materials (TLMs) are tools used by teachers to help learners learn concepts with ease and efficiency. TLMs have been in existence in our educational system since ancient times.

• The role of TLMs in the classroom is to make learning real, practical and fun for children. Teachers use TLMs to illustrate or reinforce a skill, fact or idea.
• TLMs also help in bringing novelty and freshness in classroom teaching as it relieves learners from anxiety, fear and boredom. Teaching-learning materials provide a range of learning experiences to learners from direct to indirect.

Key Points

Teachers should guide and facilitate students to construct simple TLMs themselves. Students should be divided into groups and each group be assigned the task of design and development of TLMs. As a teacher, you may adopt many strategies in motivating students.

In an activity aids, the learner directly involves through participation and direct experience. These type of teaching aids are really of great value as they put students in the role of an active constructor of knowledge. Following are some important activity teaching aids, listed below:-

• Field Trip
• Demonstration
• Experiments
• Dramatization

Thus, it is clear that an overhead projector is not an activity aids related to teaching-learning materials.
Additional Information

Overhead Projector (OHP) helps in displaying still visual material as a projection on a screen. It is a simple projector which is very easy to operate and therefore, popular among teacher. It is better than using a chalkboard as it helps teachers talk and show visuals simultaneously. As a teacher, you can observe the reaction of students and interact with them. It also helps in saving time as you can use these visuals/transparencies again and again. OHP does not require a darkened room and is easy to handle and transport from one classroom to another.

Learning takes place by comparing previous knowledge and experience with the present learning experience through thinking and activities. Learning is a universal skill seen in all species. Thinking and Learning are two interwoven activities that help to develop knowledge, critical thinking, and creative thinking.

Key Points

•  Despite the addition of more specialized disciplines and subject instructors, experiential learning within each subject and investigations of relationships among different subjects will be encouraged and highlighted.
• Experiential learning will be implemented at all levels, with investigations of the connections between various disciplines as well as hands-on learning, education that incorporates the arts and sports, and pedagogy centered on telling stories, among others, as normal practices within each subject.
• Classroom activities will change to competency-based learning and teaching to address the achievement gap in learning outcomes. Additionally, the assessment instruments—including assessment "as," "of," and "for" learning—will be in line with the learning objectives, skills, and attitudes that are listed for each subject in a given class.
• Each subject's curriculum will be edited down to the fundamentals in order to allow room for critical thinking and more all-encompassing, inquiry-based, discovery-based, discussion-based, and analysis-based learning.

Hence, National Education Policy 2020 proposes that experiential learning should be encouraged to promote critical thinking. 

Aarav's behavior suggests that he may be experiencing difficulty with his vision, such as nearsightedness or myopia, which can cause him to need to sit closer to the blackboard and hold the book closer to his eyes in order to see clearly.

Key Points

• The teacher should consult with school administrators and/or parents to explore the possibility of Aarav having an undiagnosed vision problem.
• Seeking professional support from an optometrist or ophthalmologist can help determine if Aarav needs corrective lenses or other interventions to improve his vision.
• If Aarav is diagnosed with a vision problem, appropriate accommodations can be made in the classroom, such as providing him with a seat closer to the blackboard or providing him with a larger print version of the reading material.

Thus, it is concluded that seeking professional support to check for low vision is the correct answer.

Related to teacher questioning is the use of teacher probes. Probing or delving occurs when a student does not respond to a teacher's question. Probes are teacher assists that support the student to answer.

Key Points  Probing:

• Probing helps students to clarify their thinking, surface their reasoning, and explore alternative perspectives or solutions.
• A probing question makes a student think more deeply about the topic at hand, thereby engaging him/her in more cognitively rigorous instruction.
• This is especially important for lower-achieving students who may have begun to doubt their own capabilities and withhold effort.
• Seeing their teachers make a special effort to help them can enhance students’ self-confidence and willingness to exert effort in learning.
• The question stems that follow are examples of teacher probes that can support students to think more deeply.

Hence, the approach that encourages students to elaborate on an answer - either their own or another student is called probing.

Additional Information

• Structuring is defined by Hospel and Galand (2016) as “the amount and the clarity of information given to students about how to satisfy teachers' expectations and achieve the desired educational outcomes.”
• Teacher task orientation is a key behavior that refers to how much classroom time the teacher devotes to the task of teaching.
  • The more time dedicated to the task of teaching a specific topic, the greater the opportunity students have to learn.
• Remediation is also colloquially known as “re-teaching,” as it assumes that the student has been introduced to concepts previously but has not yet mastered them.
  • Remediation enables teachers to spot blind spots in students' learning and quickly assess and correct them.

Teaching Aids is very necessary nowadays for effective teaching. Through teaching aids, the teacher clarifies the subject matter more easily.
Advantages of Teaching Aids: 

• Teaching aids make learning permanent.
• Teaching aids are helpful in attracting the desire and attention of the students.
• This makes teaching reinforced and effort practice accurate.
• It facilitates group and self-learning.
• Teaching aids provide good substitutes for the real objects as they make learning equally meaningful. 

Key Points

Types of teaching aids: 

1. Visual Aids: Charts, diagrams, graphs, etc. are effective visual aids that teachers use to convey concepts and lessons with more clarity and effectiveness.
2. Audio Aids: Using audio teaching aids will help that segment to a great extent. The effect of music on the brain has been proven. Hence, some teachers play music in the classroom to destress their students and increase their interest in the lessons.
3. Audio-Visual Aids: Videos and animations are used in the classroom to explain concepts better. With the development of technology, students have the opportunity to actually see how digestion takes place, understand the water cycle, can understand the motion of vehicles, everything can be explained everything in a much detailed and better manner.

Hence, we can conclude that the right answer to this question is All of the above.

The Assessment process should not be boring, or it should be on the basis of only one aspect. The teacher should be careful about using a variety of ways to collect information, about the students learning across scholastic and co-scholastic boundaries. Only scholastic areas should not be focused on assessment. It should also include co-scholastic areas.
Hence, the correct answer is, 'Using a variety of ways to collect information about the students learning across scholastic and co-scholastic boundaries.'

The tradition of bee-keeping in Bihar is very old. The period of October to December is considered as the best to start bee-keeping because at that time number of flowering and crop plants is more. So bees will get nectar and pollen easily to increase the production of honey. There was a setback to the bee-keeping industry in the 1980s due to the disease caused by the Thai sacbrood virus.
Hence, the correct answer is, 'October to December.'

Sarita's teacher is following learning as a social activity. Group work creates more opportunities for critical thinking and can promote student learning and achievement. Student group work enhances skills like communication and other professional development skills. All of these skills are critical to successful teamwork in the classroom.
Hence, the correct answer is, 'Learning as a social activity.'

r% of r = 49
r² = 49 × 100
r = 7 × 10 = 70
Hence, Option B is correct.