#neet

3 questions

Match List - I with List - II.List - I (Hydrides): (a) MgH_2 (b) GeH_4 (c) B_2H_6 (d) HFList - II (Nature): (i) Electron precise (ii) Electron deficient (iii) Electron rich (iv) IonicChoose the correct answer from the options given below : Answer: 2. (a) - (iv), (b) - (i), (c) - (ii), (d) - (iii) Key idea: classify hydrides by electron count. MgH₂ : metal hydride of s-block, io... Electronic configuration and general trends, Group 13 and 14 1 answer
Given below are two statements :Statement I :The acidic strength of monosubstituted nitrophenol is higher than phenol because of electron withdrawing nitro group.Statement II :o-nitrophenol, m-nitrophenol and p-nitrophenol will have same acidic stren… Answer: 4. Statement I is correct but Statement II is incorrect. Key idea: the -NO₂ group is electron withdrawing and stabilises the phenoxi... Phenols: acidity, electrophilic substitution, Reimer-Tiemann 1 answer
Match List - I with List - II.List - I (Drug class): (a) Antacids (b) Antihistamines (c) Analgesics (d) AntimicrobialsList - II (Drug molecule): (i) Salvarsan (ii) Morphine (iii) Cimetidine (iv) SeldaneChoose the correct answer from the options given… Answer: 3. (a) - (iii), (b) - (iv), (c) - (ii), (d) - (i) Key idea: match each drug class with a standard example. Antacids: cimetidine (iii... Hormones (general introduction) 1 answer
The incorrect statement regarding enzymes is : Answer: 4. Enzymes are polysaccharides. Key idea: enzymes are (almost all) globular proteins, not polysaccharides. Statements 1 to 3 are tru... Enzymes 1 answer
Identify the incorrect statement from the following. Answer: 1. The shapes of d_xy , d_yz , and d_zx orbitals are similar to each other ; and d_(x²-y²) and d_z² are similar to each other. Key i... Quantum numbers and shapes of s, p, d orbitals 1 answer
The incorrect statement regarding chirality is : Answer: 4. Enantiomers are superimposable mirror images on each other. Key idea: enantiomers are non-superimposable mirror images. Statement... Structural isomerism and stereoisomerism 1 answer
Which compound amongst the following is not an aromatic compound ? Answer: 1. [structure in figure] Key idea: an aromatic compound is cyclic, planar, fully conjugated and has (4n+2) π electrons. (1) Cyclohep... Benzene: structure and aromaticity 1 answer
The given graph is a representation of kinetics of a reaction.[Graph: y versus x at constant temperature T]The y and x axes for zero and first order reactions, respectively are Answer: 4. zero order ( y = rate and x = concentration), first order ( y = t_(1/2) and x = concenration) Key idea: a horizontal line means y... Integrated rate equations and half-life (zero and first order) 1 answer
Which one is not correct mathematical equation for Dalton's Law of partial pressure ? Here p = total pressure of gaseous mixture Answer: 1. p_i = chi_i p_i^° , where chi_i = mole fraction of i^th gas in gaseous mixture, p_i^° = pressure of i^th gas in pure state Key id... Atomic and molecular masses, mole concept, molar mass 1 answer
Given below are two statements :Statement I :Primary aliphatic amines react with HNO_2 to give unstable diazonium salts.Statement II :Primary aromatic amines react with HNO_2 to form diazonium salts which are stable even above 300 K.In the light of t… Answer: 4. Statement I is correct but Statement II is incorrect. Key idea: diazonium salts of aliphatic amines are unstable; aromatic ones a... Identification of 1/2/3 amines 1 answer
Identify the incorrect statement from the following Answer: 3. The oxidation number of K in KO₂ is +4 . Key idea: in superoxide KO₂ , oxygen is O₂^- , so K is +1. Alkali metals always show +1.... Modern periodic law and periodic table, s, p, d, f blocks 1 answer
The IUPAC name of the complex -[Ag(H_2O)_2][Ag(CN)_2] is : Answer: 1. diaquasilver(I) dicyanidoargentate(I) Key idea: in a complex salt name the cation first and then the anion; in anionic complexes... IUPAC nomenclature 1 answer
The pH of the solution containing 50 mL each of 0.10 M sodium acetate and 0.01 M acetic acid is[Given pK_a of CH_3COOH = 4.57] Answer: 2. 5.57 Key idea: acetate/acetic acid is an acidic buffer; use the Henderson equation. pH=pK_a+log[salt]/[acid] Equal volumes are mi... Buffer solutions 1 answer
Which of the following p-V curve represents maximum work done ? Answer: 3. [graph in figure] Key idea: work done by the gas equals the area under the p-V curve, so find the graph with the largest area. Gr... First law: work, heat, internal energy, enthalpy 1 answer
Match List - I with List - II.List - I (Products formed): (a) Cyanohydrin (b) Acetal (c) Schiff's base (d) OximeList - II (Reaction of carbonyl compound with): (i) NH_2OH (ii) RNH_2 (iii) alcohol (iv) HCNChoose the correct answer from the options giv… Answer: 1. (a) - (iv), (b) - (iii), (c) - (ii), (d) - (i) Key idea: link each product to the reagent used with a carbonyl compound. Cyanohyd... Aldehydes and ketones: HCN, NH3 derivatives, Grignard, oxidation, reduction (Wolff-Kishner, Clemmensen) 1 answer
Which of the following sequence of reactions is suitable to synthesize chlorobenzene ? Answer: 2. Benzene, Cl₂ , anhydrous FeCl₃ Key idea: chlorobenzene is made by electrophilic substitution of benzene with Cl₂ and a Lewis acid... Diazonium salts in synthesis 1 answer
The Kjeldahl's method for the estimation of nitrogen can be used to estimate the amount of nitrogen in which one of the following compounds ? Answer: 4. [structure in figure] Key idea: Kjeldahl's method converts N to (NH₄)₂SO₄ on digestion; it fails for N in nitro, azo groups and i... Quantitative analysis: estimation of C, H, N, halogens, S, P 1 answer
Given below are two statements :Statement I :The boiling points of aldehydes and ketones are higher than hydrocarbons of comparable molecular masses because of weak molecular association in aldehydes and ketones due to dipole - dipole interactions.St… Answer: 2. Both Statement I and Statement II are correct. Key idea: polarity of C=O gives dipole-dipole attraction but no hydrogen bonding b... Carbonyl group and nucleophilic addition, relative reactivity 1 answer
Given below are two statements :Statement I :The boiling points of the following hydrides of group 16 elements increases in the order -H_2O < H_2S < H_2Se < H_2Te.Statement II :The boiling points of these hydrides increase with increase in molar mass… Answer: 3. Both Statement I and Statement II are incorrect. Key idea: water has an abnormally high boiling point because of hydrogen bonding... General trends, Group 15 and 16 1 answer
The volume occupied by the molecules contained in 4.5 kg water at STP, if the intermolecular forces vanish away is : Answer: 1. 5.6 m ³ With intermolecular forces gone, the water molecules behave like an ideal gas, and one mole occupies 22.4 L at STP. Moles... Kinetic theory assumptions and pressure 1 answer
Two transparent media A and B are separated by a plane boundary. The speed of light in those media are 1.5 × 10^8 m/s and 2.0 × 10^8 m/s, respectively. The critical angle for a ray of light for these two media is : Answer: 3. sin⁻¹(0.750) Refractive index n=c/v : n_A=3×10⁸/1.5×10⁸=2 and n_B=3×10⁸/2×10⁸=1.5 . Total internal reflection is possible when li... Refraction at plane and spherical surfaces, thin lens and lens maker formula 1 answer
Match List - I with List - II :List - I: (a) Gravitational constant (G) (b) Gravitational potential energy (c) Gravitational potential (d) Gravitational intensityList - II: (i) [L^2T^-2] (ii) [M^-1L^3T^-2] (iii) [LT^-2] (iv) [ML^2T^-2]Choose the corr… Answer: 3. (a) - (ii), (b) - (iv), (c) - (i), (d) - (iii) Find each dimension from its formula. (a) G=Fr²/m² : [M⁻¹L³T⁻²] , so (ii) (b) Pote... Dimensions and dimensional analysis 1 answer
A series LCR circuit with inductance 10 H, capacitance 10 μF, resistance 50 Ω is connected to an ac source of voltage, V = 200 (100 t) volt. If the resonant frequency of the LCR circuit is _0 and the frequency of the ac source is , then : Answer: 3. ν₀ = ν = 50/π Hz Compare the source frequency with the resonant frequency. Source: ω=100\ rad/s⇒ν=100/2π=50/π Hz. Resonance: ω₀=1... Reactance, impedance, LCR series circuit, resonance 1 answer
A ball is projected with a velocity, 10\ ms^-1, at an angle of 60° with the vertical direction. Its speed at the highest point of its trajectory will be : Answer: 3. 5√(3)\ ms⁻¹ The angle is measured from the vertical, so the angle with the horizontal is 30^° . At the highest point only the hor... Projectile motion 1 answer

← Previous

Page 30 of 86