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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your Class 11 knowledge and support exam preparation. Choose a topic below to get started.
| 1451. |
Coordinate means |
| Answer» A coordinate bond is a covalent bond between two atoms where one of the atoms provides both electrons that form the bond. | |
| 1452. |
How many elements were discovered during the time of mendeleev?? |
| Answer» Its 63<br>In ABC book it is written that 56 elements were discovered but in other books it is 63.<br>63 elements<br>63 elements were discovered during the time Of mendeleev.<br>56 elements i think so | |
| 1453. |
Difference between delta H and delta U |
| Answer» Delta h means change in external heat energy while delta U means change in internal heat energy | |
| 1454. |
Explain bond haber cycle with suitable example. |
| Answer» Born Haber cycle is a simplified method developed by Max Born and Fritz Haber in 1919 to correlate the lattice energies of ionic solids to other thermodynamic data. Lattice enthalpy or lattice energy is defined as enthalpy change which occurs when one mole of ionic solid is formed by close packing of constituent ions in gaseous state. Or it may be defined as energy released when one mole of ionic solid dissociates into its gaseous state. For example, the formation of sodium chloride from sodium and chloride ion involves 788 kj/mol of energy and dissociation of sodium chloride into it constituent ions requires same amount of energy.NaCl(s) → Na+(g) + Cl- (g) ΔL H°= 788 kj/molNa+(g) + Cl-(g) → NaCl(s) ΔL H° = -788 kj/molWhen oppositely charged ions interact to form ionic solid, a large amount of energy is released and dissociation of crystal also require a lot of energy which makes melting point and boiling points of crystal very high. Born Haber cycle is used to determine this lattice energy by using other energy values like ionization energy, electron affinity, dissociation energy, sublimation energy and heat of formation. Ionization Energy: It is the energy required to remove an electron from a neutral gaseous atom or an ion.Electron Affinity: It is the energy released when an electron is added to an isolated neutral gaseous atom or an ion.Dissociation energy: The energy required to dissociate a compound is called as dissociation energy. Dissociation of a compound is always an endothermic process and requires an input of energy.Sublimation energy: The energy required to change the phase from solid to gas, by passing the liquid phase is called as sublimation energy.Heat of formation: The energy change during the formation of a compound from its elements is known as heat of formation.Born Haber cycle is based on Hess law which states that the standard enthalpy change of reactions is the sum of algebraic sum of the standard enthalpies of reactions into which the overall reaction may be split or divided.For example, the formation of C from A and B can take place in two ways. Both ways involve same initial and final states, but one is single step and other one is multi-step reaction which involves intermediates, D and E. Both ways has an enthalpy change of 160 kJ.<br>The Born–Haber cycle is an approach to analyze reaction energies. It was named after the two German scientists Max Born and Fritz Haber, who developed it in 1919.[1][2][3] It was also independently formulated by Kasimir Fajans.[4] The cycle is concerned with the formation of an ionic compound from the reaction of a metal (often a Group I or Group II element) with a halogen or other non-metallic element such as oxygen.Born–Haber cycles are used primarily as a means of calculating lattice energy (or more precisely enthalpy[note 1]), which cannot otherwise be measured directly. The lattice enthalpy is the enthalpy change involved in the formation of an ionic compound from gaseous ions (an exothermic process), or sometimes defined as the energy to break the ionic compound into gaseous ions (an endothermic process). A Born–Haber cycle applies Hess\'s law to calculate the lattice enthalpy by comparing the standard enthalpy change of formation of the ionic compound (from the elements) to the enthalpy required to make gaseous ions from the elements.This latter calculation is complex. To make gaseous ions from elements it is necessary to atomise the elements (turn each into gaseous atoms) and then to ionise the atoms. If the element is normally a molecule then we first have to consider its bond dissociation enthalpy. The energy required to remove one or more electrons to make a cation is a sum of successive ionization energies; for example, the energy needed to form Mg2+ is the ionization energy required to remove the first electron from Mg, plus the ionization energy required to remove the second electron from Mg+. Electron affinity is defined as the amount of energy released when an electron is added to a neutral atom or molecule in the gaseous state to form a negative ion.The Born–Haber cycle applies only to fully ionic solids such as certain alkali halides. Most compounds include covalent and ionic contributions to chemical bonding and to the lattice energy, which is represented by an extended Born-Haber thermodynamic cycle.[5] The extended Born–Haber cycle can be used to estimate the polarity and the atomic charges of polar compounds. | |
| 1455. |
How an entropy of the reaction and its enthalpies can be corelated to each other? |
| Answer» | |
| 1456. |
What is absorption spectra |
| Answer» The spectrum formed by electromagnetic radiation that has passed through a medium in which radiation of certain frequencies is absorbed.<br>Absorption spectra is the opposite of emission spectrum , where energy, light or radiation is absorbed by the electrons of a particular matter. | |
| 1457. |
What is radiation? |
| Answer» Radiarion is the energy radiated or transmitted in the form of rays, waves, or particles.(OR)A stream of particles or electromagnetic waves that is emitted by the atoms and molecules of a radioactive substance as a result of nuclear decay.<br>radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. | |
| 1458. |
Tomorrow is my practical exam so what are the questions come in that |
| Answer» Salt analysis | |
| 1459. |
Whart is redox couple |
| Answer» Ok<br>Ya this answer is correct.it is definition of redox couple which was given by my mam in school<br>Redox couple. Defined as having together the oxidised and reduced forms of a substance taking part in oxidation or reduction half-reaction.<br>The pair of an oxidizing and reducing agent that are involved in a particular reaction is called a redox pair or redox couple. | |
| 1460. |
formula of carbohydrates |
| Answer» \'Hydrated carbon\' CH2O | |
| 1461. |
What is Quantum numbers? |
| Answer» Then you rectify it..<br>You only said it specify the position and energy of electron<br>Prabhat, what\'s missing here??????<br>What is missing here??????????<br>But something is missing in your answer<br>Quantum numbers are the index numbers which are used to specify the position and energy of an electron in an atom. ORQuantum numbers are the constants obtained by solving schrodinger wave equation that provides detailed address o an electron in an atom. 4 types of quantum numbers:1. Principal quantum number,2. Azimuthal quantum number,3. Magnetic quantum number,4. Spin quantum number. | |
| 1462. |
calculate sigma and pi bond in CH3-C=CHCH2CH3 |
| Answer» 13 sigma and 1 pi bond is there for this<br>??no, i m not???it\'s my way to give someone answer....???<br>R u confused with ur answer.... By the way, it\'s correct...<br>I hope it\'s clear?<br>It\'s so easy just make complete structure and then calculate no. Of single bonds with hydrogens too....total no. Of single bonds are sigma bond and no. Of double or triple bonds in a compound are known as pie bond like in this question ......there is one double bond so...total no. Of pie bond is 1 | |
| 1463. |
Defination of formal charge in easy language.. |
| Answer» Formal charge (FC) is the charge assigned to an atom in a molecule, assuming that electrons in all chemical bonds are shared equally between atoms, regardless of relative electronegativity.Formal Charge of valence electrons on atom= [non-bonded electrons + number of bonds]. | |
| 1464. |
What is nucleophile |
| Answer» Nucleophile is a chemical species that donates an electron pair to an electrophile to form a chemical bond in relation to a reaction. All molecules or ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are by definition Lewis bases.<br>Pata nahi bhai | |
| 1465. |
What is the effect of temperature on rate of reaction, rate constant & equilibrium constant. |
| Answer» | |
| 1466. |
Second law of thermodynamics states what |
| Answer» The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time. The total entropy can remain constant in ideal cases where the system is in a steady state, or is undergoing a reversible process.<br>S.L Arora<br>S.L me page no 12.23 pe dekh lo mil jayaga | |
| 1467. |
What is Kepler\'s laws |
| Answer» Kepler’s 1st Law: Law of OrbitsStatement: - The orbit of every planet is an ellipse around the sun with sun at one of the two foci of ellipse.Kepler’s 2nd law: Law of AreasStatement:-The line that joins a planet to the sun sweeps out equal areas in equal intervals of time.Kepler’s 3rdLaw: Law of periodsStatement: -\tAccording to this law the square of time period of a planet is ∝ to the cube of the semi-major axisof its orbit.\tSuppose earth is revolving around the sun then the square of the time period (time taken to complete one revolution around sun) is ∝ to the cube of the semi major axis.\tIt is known as Law of Periods as it is dependent on the time period of planets. | |
| 1468. |
BF3 has zwro dipole moment although thw B-F bonds are polar.why? |
| Answer» In BF3 case all the resultant dipoles will cancel each other . Hence , it is non polar .<br>In B----F. F has high electronegativity so the electron which has been shared would shift towards F . F will posses partial -ve charge and B will get partial +ve charge. Hence , it is polar. | |
| 1469. |
What is chemical equilibrium |
| Answer» chemical equilibrium is the state in which both reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system | |
| 1470. |
Why there are two value of Rydberg constant? |
| Answer» | |
| 1471. |
Explain the stability of half filled and full filled |
| Answer» Ok... ?<br>I Only know that half filled or full filled orbitals are more stable than other orbitals<br>Orbitals<br>....... | |
| 1472. |
Hyperconjugatin in organic chemistry |
| Answer» | |
| 1473. |
Pcl5 is more covalent than pcl3.why? |
| Answer» You just see the Lewis dot structure of PCl5 and PCl3 | |
| 1474. |
Whats happen to the ph if a few drops of hcl is added to ch3coonh4 solution |
| Answer» | |
| 1475. |
Explain hydrogen bond write its signification |
| Answer» Hydrogen has one valence electron in its only shell . It shares it\'s electron with other hydrogen atom and form h-h bond. It\'s Lewis structure (h:h) .<br>simple way to explain hydrogen bonds is with water. Since oxygen is more electronegative than hydrogen, oxygen pulls the shared electrons more closely to itself. This gives the oxygen atom a slightly more negative charge than either of the hydrogen atoms. | |
| 1476. |
Calculate the energy of first orbit of He+ ion and what is its radius |
| Answer» Radius is 12pm<br>Energy is 13.6 eV | |
| 1477. |
Why we are useing active mass[ ] in equilibrium |
| Answer» Square bracket [ ] denots the concentration.<br>Actuve mass word is used for concentration term Kc in the chapter | |
| 1478. |
a hydrocarbon on complete combustion give 0.33g of CO2 and 0.18 g of H2O. the empirical formulae is |
| Answer» Then go for related questions of it... Other than that I don\'t know sry... ?<br>ok but i don\'t get it from any website so what can i do<br>Hlo<br>For urgency, u can go to any other websites on net....<br>pls answer this its urgent ? | |
| 1479. |
What is the common name for propan3 ene |
| Answer» | |
| 1480. |
Expain hybridization in SF6 |
| Answer» Octahedral. | |
| 1481. |
What are monomeric trihalides ? |
| Answer» | |
| 1482. |
H2SO4 +br > |
| Answer» H2so4 + 2br = br2so4 + h2 | |
| 1483. |
How can we estimate the amount of oxygen in an organic compound? |
| Answer» | |
| 1484. |
How do you convert fructose to glucose? |
| Answer» Glucogenesis | |
| 1485. |
Which have more entropy ice or water & why |
| Answer» It\'s water because its molecules have more disorder and random motions. More disorder more entropy.<br>It\'s water.Because its molecules have more disorder and random motions. More disorder more entropy. | |
| 1486. |
How we find lone pair and bond pair |
| Answer» | |
| 1487. |
What is fajan rule? |
| Answer» Smaller the cation and larger the anion more will be covalent character (in a compound). | |
| 1488. |
Explain Lewis acid and base |
| Answer» Lewis acid are those compounds that accept a lone pair to complete there octet example. Bf3 Lewis base are those compound that donate a lone pair because of expanded octet | |
| 1489. |
What will be the volume of hydrogen when 3L of it are cooled from 15° C to 73°C at constant pressure |
| Answer» | |
| 1490. |
what is the oxidation number of Ca in CaSO4? |
| Answer» Oxidation no. Of ca is+2<br>Oxidation of O is -2 (4×-2= -8)Oxidation of S is 6 (6×1 = 6)Let oxidation of ca x then Total is zero x+6-8 =0Or x= 2<br>In CaSO4 , oxidation number of Ca is +2<br>+2is the oxidation number of ca in caso4 | |
| 1491. |
Where find unstable particles in any atom. ...?? |
| Answer» | |
| 1492. |
The ionic radius of f is 136pm where as the atomic radius of E is 36 pm explain why? |
| Answer» | |
| 1493. |
Can we store copper sulphate solution in iron vessel.Explain why |
| Answer» No => CuSO4 + Fe------> FESO4 + CU (NO it can react with Fe and form FeSO4)<br>No | |
| 1494. |
Calculate the molar mass of H2O? |
| Answer» Molar mass of H2O is 18<br>18<br>18<br>18<br>18<br>18 | |
| 1495. |
1metre cube of C2H5 |
| Answer» | |
| 1496. |
Is solid state (states of matter) is in syllabus? |
| Answer» Yes it is there this year<br>Yes,it is newly added chapter in syllabus<br>Not in class 11 but in class 12<br>It is there.but in ncert it is not there in detail<br>No ..not detailed .there is only gases and liquids states<br>Yah!<br>Yes | |
| 1497. |
What is the position of hyfrogen in periodic tablr |
| Answer» There is no any fixed position of hydrogen in modern periodic table<br>The actual position of hydrogen is not known till now but its valency is 1 so it is place at the 1st group at is first position | |
| 1498. |
Name the two types of bonds present in diborane. |
| Answer» | |
| 1499. |
How to check reaction is reversible |
| Answer» | |
| 1500. |
Define term Domain ? |
| Answer» Using mathematics concept of set<br>the first element of the ordered pair is called domine . Eg in (2,3) 2 is the domine the second element of the ordered pair is called range and 3 is the range | |