Popular Chemistry Online: August 2021

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Sunday, August 29, 2021

KISHORE VAIGYANIK PROTSAHAN YOJANA (KVPY) FELLOWSHIP AWARD - 2021

APPLICATIONS ARE INVITED FROM SCHOOL AND COLLEGE STUDENTS INTERESTED IN PURSUING BASIC SCIENCE COURSES AND CAREER IN RESEARCH   

 The Kishore Vaigyanik Protsahan Yojana (KVPY) is a National level fellowship program in Basic Sciences.  It is driven by the Department of Science and Technology, Government of India. The main motive of the program is to attract the talented and merit students towards pursuing basic science courses and research career in science.  The program encourages the students to participate in the research and development in the country by offering them scholarship benefits every month in the name of contingency grant. KVPY has rolled out its notification inviting the eligible candidates to apply for the fellowship.  The applications were being accepted starting from July 12, 2021. Applicants need to take up the aptitude test conducted by KVPY through computer-based mode. The KVPY Exam Pattern plays a key role in preparation for the aptitude test.

for the uninitiated, KVPY is a scholarship exam conducted every year to the students pursuing under graduation degree.  It offers monthly scholarships to the selected students and also conducts summer camps for them. In this article, we are going to talk about the KVPY syllabus.  Applicants who have already applied for the KVPY exam are advised to download the KVPY syllabus and KVPY Exam Pattern from online.  Students can also get a sneak peek into the syllabus of KVPY aptitude exam from our page. We have also covered entire syllabus of KVPY online based computer exam.

Candidates before starting their preparation should refer to the syllabus to know the topics that are going to be covered in the KVPY question paper.  The exam body itself prescribed the syllabus for all the three existing streams – SA, SB and SX. Students should download the respective stream wise KVPY Exam Syllabus from the official web portal and can also check the same from our page here.  The aptitude test is slated to be held on 7th November 2020.  Though there is enough time left for the exam, students should heed in mind that it is highly competitive exam and is difficult to crack.  So, students need to start their preparation by first downloading the stream wise syllabus.

If you have any queries regarding KVPY Syllabus 2021, simply leave your query in the comments section below.  Bookmark our website – KVPY.ORG.IN for updated information.

IMPORTANT DATESS 
Start of online submission of Application 12th July 2021 
Last date for closing of online Application 6th September 2021 
KVPY Aptitude Test 7 th November 2021 





KVPY Syllabus For SA

The KVPY SA syllabus for stream SA consists of all the topics and chapters from Class X and XI.  The four major subjects that are covered in SA stream include Physics, Chemistry, Biology and Mathematics.

  • Physics: Applications in Daily Life, Kinematics, Laws of Motion, Work, Energy and Power, Physical World and Measurement, Gravitation, Thermodynamics, Magnetic Effects of Current, Sources of Energy, Reflection, Refraction, Electromagnetic Induction.
  • Chemistry: Thermodynamics, States of Matter: Gases and Liquids, Classification of Elements and Periodicity in Properties, Environmental Chemistry, Chemical Reactions, Metals and Nonmetals, Periodic Classification of Elements, Carbon Compounds, Acids, Bases and Salts, Basic Concepts of Chemistry.
  • Mathematics: Coordinate Geometry, Mathematical Reasoning, Statistics and Probability, Trigonometric Functions, Real Numbers, Polynomials, Geometry, Introduction to Trigonometry, Statistics, Quadratic Equations, Probability, Surface Areas, and Volumes.
  • Biology: Plant Physiology, Diversity of Living Organisms, Cell: Structure and Function, Human Physiology, Control and Coordination in Animals and Plants, Heredity and Evolution, Reproduction, Life Processes, Our Environment.

KVPY Syllabus For SX

The KVPY SX syllabus covers the topics and chapters form classes Class X, XI & XII.  Again the same four subjects are covered in the syllabus – Physics, Chemistry, Biology and Mathematics.  It is just that the KVPY Syllabus for Class 12 is added for SX stream.

  • Physics: Thermodynamics, Electrostatics, Refraction, Current Electricity, Electromagnetic Induction and Alternating Current, Magnetic Effects of Current, Reflection of Light, Electromagnetic Induction, Kinematics, Work, Energy and Power, Sources of Energy, Physical World and Measurement, Gravitation, Laws of Motion.
  • Chemistry: Chemical Reactions, Environmental Chemistry, Solid State, Electrochemistry, Chemical Kinetics, Isolation of Elements, Periodic Classification of Elements, Surface Chemistry, States of Matter: Gases and Liquids, Metals and Nonmetals, Carbon Compounds, Basic Concepts of Chemistry, Thermodynamics, Classification of Elements and Periodicity in Properties.
  • Biology: Human Physiology, Biology and Human Welfare, Control and Coordination in Animals and Plants, Ecology and Environment, Cell: Structure and Function, Genetics and Evolution, Life Processes, Plant Physiology, Diversity of Living Organisms, Reproduction.
  • Mathematics: Trigonometric Functions, Geometry, Linear Programming, Vectors and 3D Geometry, Calculus, Relations and Functions, Coordinate Geometry, Mathematical Reasoning, Real Number, Polynomials, Introduction to Trigonometry, Surface Areas and Volumes, Statistics and Quadratic Equations, Probability, Statistics, and Probability.

KVPY Syllabus For SB

In this KVPY SB Syllabus, along with class 10th and 12th syllabus, 1st year of under graduation syllabus is also covered for the same said subjects.

  • Physics: Thermodynamics, Reflection, Electrostatics, Current Electricity, Electromagnetic Induction and Alternating Current, Waves and Optics, Electricity and Magnetism, Electrostatics and Thermal Physics, Electromagnetic Induction, Physical World and Measurement, Sources of Energy, Refraction and its Applications in Daily Life, Kinematics, Laws of Motion, Magnetic Effects of Current, Work, Energy and Power, Gravitation.
  • Chemistry: Metals and Nonmetals, Environmental Chemistry, Solid State, Electrochemistry, Chemical Kinetics, Isolation of Elements, Surface Chemistry, Chemical Bonding, Chemistry of Noble Gases, Structure and Bonding, Alkenes, Cycloalkenes, Dienes and Alkynes, Thermodynamics, Chemical Reactions, Basic Concepts of Chemistry, Periodic Classification of Elements, Carbon Compounds, Acids, Bases and Salts, States of Matter: Gases and Liquids, Classification of Elements and Periodicity in Properties.
  • Biology: Plant Physiology, Reproduction, Diversity of Living Organisms, Cell: Structure and Function, Biology and Human Welfare, Biotechnology, Genetics, Life Processes, Human Physiology, Control and Coordination in Animals and Plants, Genetics and Evolution, Our Environment, Ecology and Environment.
  • Mathematics: Coordinate Geometry, Mathematical Reasoning, Statistics and Probability, Trigonometric Functions, Linear Programming, Relations and Functions, Analytical Geometry in Two Dimensions, Vector Algebra, Evaluation of Integrals, Statistics, Surface Areas and Volumes, Vectors and 3D Geometry, Calculus, Real Number, Polynomials, Geometry, Introduction to Trigonometry, Quadratic Equations, Probability.
  • KVPY Aptitude Test 2021 will be held in the following cities across India:

    East & North East: Bhagalpur, Muzaffarpur, Patna (Bihar), Bhilai nagar, Bilaspur, Raipur  (Chhattisgarh), Bokaro, Dhanbad, Jamshedpur, Ranchi (Jharkhand), Berhampur, Bhubaneshwar,  Cuttack, Rourkela, Sambalpur (Orissa), Naharlagun (Arunachal Pradesh), Dibrugarh, Guwahati, Silchar, Tezpur (Assam), Imphal (Manipur), Shillong (Meghalaya), Agarthala (Tripura), Asansol, Burdwan, Durgapur, Hoogly, Kalyani, Kolkata, Siliguri (West Bengal)

    North: Chandigarh (Chandigarh), New Delhi (Delhi), Ambala, Faridabad, Gurugram, Hisar, Karnal, Kurukshetra,  Rohtak, Sonipat (Haryana), Jammu (Jammu & Kashmir), Amritsar, Bhatinda, Jalandhar, Ludhiana, Mohali, Patiala (Punjab), Ajmer,  Bikaner, Jaipur, Jodhpur, Sikar, Udaipur (Rajasthan),  Agra, Bareilly, Ghaziabad, Gorakhpur, Jhansi, Kanpur, Lucknow, Meerut, Moradabad, Noida, Prayagraj, Varanasi (Uttar Pradesh), Dehradun, Haldwani, Roorkee (Uttarakhand)

    South: Kurnool, Rajahmundry, Tirupathi, Vijayawada, Visakhapatnam (Andhra Pradesh), Belagavi, Bengaluru, Bidar, Chikkaballapura, Chikkamangaluru,  Davanagere, Hassan, Hubballi/Dharwad, Kalaburagi,  Mangaluru, Mysuru, Puttur, Shivamogga, Udupi, (Karnataka), Hyderabad, Warangal (Telangana), Alappuzha, Ernakulam, Idukki, Kannur, Kasaragod, Kollam, Kottayam, Kozhikode, Malappuram,  Pathanamthitta, Palakkad, Thiruvananthapuram, Thrissur (Kerala), Puducherry (Puducherry), Chennai, Coimbatore, Kanchipuram, Madurai, Nagercoil, Salem, Tiruchirappalli, Tirunelveli, Vellore (Tamil Nadu)

    West & Central: Madgoan, Panaji (Goa), Ahamedabad, Anand, Gandhinagar, Rajkot, Surat, Vadodra (Gujarat), Bhopal, Gwalior, Indore, Jabalpur, Ujjain (Madhya Pradesh), Amaravati, Aurangabad, Jalgaon, Kolhapur, Mumbai, Nagpur, Nashik, Navi Mumbai, Pune, Thane (Maharashtra)

     


Saturday, August 21, 2021

SAMADHAN-III scholarship 2021

 


A step forward with an objective of Digital-INDIA, the organization has come up with an idea of new era online exam. This online exam system is going to benefit candidates in many ways. The exam will be conducted online, unlike other online exam; it can be accessed from any android device at any location having internet connection .

EVENT

DATE

REGISTRATION START:

07.08.2021 (12:00 Hrs)

REGISTRATION ENDS:

19.09.2021 (23:59 Hrs)

EXAM DATE:

03.10.2021

Answer Keys & Objections (if any):

04.10.2021

RESULT DATE:

06.10.2021

SCHOLARSHIP DISTRIBUTION : 11.10.2021

TYPES OF SCHOLARSHIP:

Types of Scholarship

Scholarship Amount

Type A scholarships

(60% & above marks)

Rs.1000

Type scholarships

(above 50% & below 60% marks)

Rs.500

Type scholarships

(above 40% & below 50% marks)

Rs.300

NOTES:

  No Registration fee for all categories i.e. GEN/OBC/SC/ST 

B. ELIGIBILITY:

- 10th, 12th, Graduation, Post-Graduation, any degree or diploma (10th is minimum qualification candidate with higher qualification are eligible to apply)

 - Age: 16-40 years

C. MEDHAVI Scholarship REGISTRATION shall be done via Medhavi Android application only. Application can be downloaded from Play Store or below link :

CLICK HERE TO DOWNLOAD MEDHAVI APPLICATION/Registration 

The more details about this SAMADHAN-III scholarship 2021 is given below-

Friday, August 13, 2021

Competency based question -Hydrogen

 1)    If same mass of liquid water and a piece of ice are taken, then why is the density of ice less than that of liquid water?

Sol: The mass per unit volume (i.e., mass/volume) is called density. Since water expands on freezing, therefore, volume of ice for the same mass of water is more than liquid water. In other words, density of ice is lower than liquid water and hence ice floats on water.

2)        Give reasons:

(i)   Lakes freeze from top towards bottom.

(ii)   Ice floats on water.

Sol: (i) During severe winter, the temperature of water in the lake keeps on decreasing. Since cold water is heavier, it keeps on going into the interior of the lake while warm water keeps on coming to the surface of the lake. This process continues till the temperature of entire water of lakes becomes 4°C. Since density of water is maximum at 277 K, any further decrease in the temperature will decrease its density. As a result, the temperature of the surface water keeps on decreasing and it ultimately freezes. Now, any further decrease in the temperature will decrease the temperature of water below 4°C. This process continues and as a result, the lakes keep on freezing from top to bottom.

(ii) Density of ice is less than water due to presence of empty spaces created because of H- bonding between H20 molecules. Hence, ice floats on water.

3)    When the first element of the periodic table is treated with dioxygen, it gives a compound whose solid state floats on its liquid state. This compound has an ability to act as an acid as well as a base. What products will be formed when this compound undergoes autoionisation?

Sol: The first element is hydrogen and its molecular form is dihydrogen (H2). It reacts with oxygen to form water whose solid state is ice which is lighter than water and floats over water.

Water is amphoteric in nature, i.e., it acts as an acid in the presence of strong bases and acts as a base in the presence of strong acids.

4)    Rohan heard that instructions were given to the laboratory attendant to store a particular chemical, i.e., keep it in the dark room, add some urea in it, and keep it away from dust. This chemical acts as an oxidizing as well as a reducing agent in both acidic and alkaline media. This chemical is important for use in the pollution control treatment of domestic and industrial effluents.

(i)   Write the name of this compound.

(ii)   Explain why such precautions are taken for storing this chemical.

Sol: (i) The name of the compound is H202. It acts as an oxidizing as well as reducing agent in both acidic and basic media.

(ii) H202 is decomposed by light and dust particles. Urea is added as a negative catalyst, i.e., to check its decomposition.                             

2H202(1)→2H20(1) + 02(g)

Because of the oxidizing properties, H202 is widely used to control pollution by oxidation of harmful cyanides and obnoxious smelling sulphides present in domestic and industrial effluents. It also helps in sewage disposal by supplying 02 for oxidation of organic matter present – in sewage waters.

5)    Arrange the following

(i)   CaH2, BeH2 and TiH2 in order of increasing electrical conductance.

(ii)   LiH, NaH and CsH in order of increasing ionic character.

(iii)    H–H, D–D and F–F in order of increasing bond dissociation enthalpy.

(iv)   NaH, MgH2 and H2O in order of increasing reducing property.

Sol: (i) The electrical conductance of a molecule depends upon its ionic or covalent nature. Ionic compounds conduct, whereas covalent compounds do not.

BeH2 is a covalent hydride. Hence, it does not conduct. CaH2 is an ionic hydride, which conducts electricity in the molten state. Titanium hydride, TiH2 is metallic in nature and conducts electricity at room temperature. Hence, the increasing order of electrical conductance is as follows:

   BeH2 < CaH2 < TiH2

(ii)   The ionic character of a bond is dependent on the electronegativities of the atoms involved. The higher the difference between the electronegativities of atoms, the smaller is the ionic character.

Electronegativity decreases down the group from Lithium to Caesium. Hence, the ionic character of their hydrides will increase (as shown below).

    LiH < NaH < CsH

(iii)   Bond dissociation energy depends upon the bond strength of a molecule, which in turn depends upon the attractive and repulsive forces present in a molecule. 

The bond pair in D–D bond is more strongly attracted by the nucleus than the bond pair in H–H bond. This is because of the higher nuclear mass of D2. The stronger the attraction, the greater will be the bond strength and the higher is the bond dissociation enthalpy. Hence, the bond dissociation enthalpy of D–D is higher than H–H.

However, bond dissociation enthalpy is the minimum in the case of F–F. The bond pair experiences strong repulsion from the lone pairs present on each F-centre.

Therefore, the increasing order of bond dissociation enthalpy is as follows:

 F–F < H–H < D–D

(iv)   Ionic hydrides are strong reducing agents. NaH can easily donate its electrons. Hence, it is most reducing in nature.

Both, MgH2 and H2O are covalent hydrides. H2O is less reducing than MgH2 since the bond dissociation energy of H2O is higher than MgH2. 

Hence, the increasing order of the reducing property is H2O < MgH2 < NaH.

6)  Why the solution H2O2 did not concentrated on heating? How it can be concentrated? Sol: Hydrogen peroxide obtained by any method is dilute. It cannot be concentrated by boiling because it decomposes at a temperature below its boiling point. Therefore it is concentrated by following step:

a.   Evaporation:

Evaporation of dilute solution of H2O2 on water bath at 70°C gives 45 – 50% H2O2 solution.

b.   Vacuum evaporation:

The evaporation is further carried on, in a vacuum desiccator over concentrated sulphuric acid. In this way 66% solution of hydrogen peroxide is obtained.

 

c.   Distillation under reduced pressure:

66% solution of hydrogen peroxide on distillation under reduced pressure, yields hydrogen peroxide of 99% concentration.

 d.   Crystallization:

H2O2 solution obtained in the above step is placed in a freezing mixture of solid CO2 and ether. Crystals of H2O2 formed are separated and melted to obtain pure H2O2.

 7)    For the manufacture of hydrogen peroxide from peroxides, phosphoric acid is more useful than sulphuric acid why?

Sol: H2SO4 acts as catalyst in the decomposition of H2O2. So for the manufacture of H2O2 from peroxides instead of H2SO4, weak acids like H3PO4, H2CO3 etc. are more useful.

3BaO2 + 2H3PO4 → Ba3(PO4)2 + 3H2O2

8)    An ionic crystal of an alkali metal has significant covalent character and is almost unreactive towards oxygen and chlorine. This is used in the synthesis of other useful hydrides. Write the formula of this hydride? Write its reaction with Al2Cl6?

Sol:

The hydride is LiH. Due to Li it behaves as covalent compound. It is highly stable.

8LiH + Al2Cl6 → 2LiAlH4 + 6LiCl

9)    Why hard water does not give fast lather with soap? Sol:

In hard water bicarbonate, chlorides and sulphates of Ca and Mg are present. Soaps are sodium salt of higher fatty acids e,g., sodium stearate(C17H35COONa). (MPBoardSolutions.com) Salts of calcium and magnesium react and form precipitates of calcium and magnesium stearate.

2C17 H35 COONa + M2+ → (CH17 H35 COO)2 M + 2Na+

Until all the salts are precipitated, no lather is formed with soap and this soap is wasted.

 10)     What is conducting water? Write their uses? 

Sol:Kohlrausch distilled the water 42 times at low pressure in an aperture made up of quartz.

This water is called conducting water. This is used for conductivity.

11)     Explain why HCI is a gas and HF is a liquid? Sol:

F is smaller and more electronegative than Cl, so it forms stronger H – bonds as compared to Cl. As a consequence, more energy is needed to break the H – bonds in HF than HCI and hence the boiling point of HF is higher than that of HCI. That’s why HF is liquid and HCI is a gas.

12)     Why H2O2  is called Antichlor? Sol:

In neutral medium H202 reduce halogen to acid, metal oxides to metals and ozone to 02.

Cl2  + H2O2   2HCl + O2 Br2  + H2O2   2HBr + O2.

Due to its ability to reduce chlorine it acts as an Antichlor in bleaching by destroying the unreacted chlorine.

13)     Do you expect the carbon hydrides of the type (Cn H2n+2) to act as Lewis acid or base? Justify your answer?

Sol:

CnH2n+2  such as CH4, C2H6  etc. neither act as Lewis acid nor Lewis base. It is because octet of all the carbon atoms are completed.

14)     In which compound the oxidation number of hydrogen is negative? Sol:

When hydrogen reacts with higher metal or highly reactive metals like Na, K, Ca etc then electrovalent hydrides are formed. In this hydride the hydrogen has negative oxidation state.

15)     On the basis of electronic configuration justify the position of hydrogen in periodic table?

Sol:

Hydrogen is the first and the lightest element of the periodic table. It is not a metal but a non – metallic element. But on the basis of electronic configuration it is kept in first group of 5 – block. It is found in atomic form only at high temperature. In elemental form it is found as diatomic molecule i.e., as H2  and is also called as dihydrogen. One proton and one electron is found in hydrogen atom. Hydrogen forms large number of compounds and is an element of high industrial importance.

Hydrogen is the first element of periodic table with one proton in the nucleus and one electron in the first shell (K – shell). It is not possible to assign a to hydrogen in Mendeleev’s and modem periodic table because it shows similarities and dissimilarities with alkali metals (IA group), halogens (VIIA group) and carbon group (IV A group). This makes position of hydrogen very controversial. Because of this it is also known as Rogue element

16)     H2O2  is used for shining the old oil paintings? Sol:


Old oil paintings contain basic lead oxide, H2S present in atmosphere change lead oxide into lead sulphide. Thus, white paintings become black.

When the paintings are washed with hydrogen peroxide black lead sulphide oxidised into lead sulphate and painting shine again.

 


17)     Describe ortho and para hydrogen. How will you obtain para hydrogen? Sol:

Hydrogen atom consists of one proton in the nucleus and one electron in the extra nuclear part. Both electron and nucleus spin about their own axis. (MPBoardSolutions.com) When two atoms of hydrogen combine to form a hydrogen molecule, the spins of electron should be in opposite direction but the spins of nuclei may either be in the same direction or in opposite directions. When nuclear spins are in same direction, it is called ortho hydrogen. When nuclear spins are in opposite directions, it is called para hydrogen.

 


 

 

Preparation of para hydrogen:

Para hydrogen can be obtained from ordinary hydrogen by keeping it in a quartz vessel with active charcoal at 20K for about 3 to 4 hours.

  18)     Why the density of water is maximum at 4°C? Sol:

Maximum density of water:

Melting of ice decreases hydrogen bonds because cage – like structure is broken. With increase in temperature from 0°C to 4°C with the cleavage of H – bonds, water molecules starts moving closer to each other as a result volume decreases while density increases. When the temperature becomes greater than 4°C, kinetic energy of H2O molecule increases resulting in expansion of water. As a result of this volume increases while density decreases. That is at 4°C, density of water is maximum.


19)     Rohan heard that instructions were given to the laboratory attendent to store a particular chemical Le., keep it in the dark room, add some urea in it, and keep it away from dust This chemical acts as an oxidizing as well as a reducing agent in both acidic and alkaline media. This chemical is important for use in the pollution control treatment of domestic and industrial effluents?

  1.     Write the name of this compound.

       2.     Explain, why such precautions are taken for storing this chemical? Sol:

1.     H2O2  (Hydrogen peroxide).

2.     The following precautions must be taken while storing hydrogen peroxide:

3.     It must be kept in wax lined coloured bottles because the rough glass surface, light and dust particles are responsible for its decomposition.

4.     A small amount of negative catalyst such as urea, glycerol, phosphoric acid etc. is generally added which retards its decomposition.

20)     Teacher told the students tat water should be softened before using in broilers. Kamala one of the students, asked the reason. The teacher explained the reason in detail to her and then Kamala got satisfied.

a)   Predict the explanation given by the teacher.

 

b)   Temporary hard water becomes soft on boiling .Why?

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