Description : Predict the two most likely mechanisms for the reaction of 2-iodohexane with sodium ethoxide. (a) SN2 and SN1 (b) E1 and E2 (c) SN2 and E2 (d) E1 and SN1
Last Answer : SN2 and E2
Description : When dipentyl ether is treated with excess HI, through what type of mechanism(s) does the major product result? (a) SN2 (b) SN1 (c) E1 (d) E2
Last Answer : SN2
Description : The acid-catalyzed dehydration mechanism for alcohols is best described as a(n) : (a) E1 . (b) E2 . (c) SN1 (d) SN2
Last Answer : E1 .
Description : Dehydrohalogenation of 2-bromobutane in the presence of a strong base proceeds via which of the following mechanistic pathways? (a) SN1 (b) SN2 (c) E1 (d) E2
Last Answer : E2
Description : Which of the following factors influence whether a reaction will proceed by an SN1, SN2, E1, or E2 mechanism? (a) Structure of the alkyl halide (b) Solvent (c) Concentration of reagents (d) Nature of the nucleophile (e) All of these
Last Answer : All of these
Description : When ethanol is heated with concentrated H2SO4, a gas is produced. Which of the following compounds is formed when this gas is treated with bromine in CCl4?E2 (a) Bromomethane (b) 1,2-Dibromoethane (c) Bromoethane (d) 1,1,2,2-Tetrabromoethane
Last Answer : 1,2-Dibromoethane
Description : Which of the following is the rate law for SN1 mechanisms? (a) Rate = k[Alkyl Halide] [Nucleophile] (b) Rate = k[Nucleophile] (c) Rate = k[Alkyl Halide] (d) Rate = k1[Alkyl Halide] + k2[Nucleophile]
Last Answer : Rate = k[Alkyl Halide]
Description : Two half-reactions of an electrochemical cell are given below : MnO-4 (aq) + 8H+ (aq) + 5e- → Mn2+ (aq) + 4H2O (I), E° = 1.51 V Sn2+ (aq) → Sn4+ (aq) + 2e- ... the redox equation from the standard potential of the cell and predict if the reaction is reactant favoured or product favoured. -Chemistry
Last Answer : The reactions can be represented at anode and at cathode in the following ways : At anode (oxidation) : Sn2+ → = Sn4+ (aq) + 2e- ] 5 E° = + 0.15 V At cathode (reduction) : MnO-4(aq) + 8H+ ... = E°cathode - E°anode = 1.51 - 0.15 = + 1.36 V ∴ Positive value of E°cell favours formation of product.
Description : Two half-reactions of an electrochemical cell are given below : MnO-4 (aq) + 8H+ (aq) + 5e- → Mn2+ (aq) + 4H2O (I), E° = 1.51 V Sn2+ (aq) → Sn4+ (aq) + ... -reactions and calculate the cell potential from the standard potentials and predict if the reaction is reactant or product favoured. -Chemistry
Last Answer : The reactions can be represented at anode and at cathode in the following ways : At anode (oxidation) : Sn2+ → Sn4+ (aq) + 2e- ] 5 E° = + 0.15 V Af cathode (reduction) : MnO-4(aq) + 8H+ ( ... = E°cathode - E°anode = 1.51 - 0.15 = + 1.36 V ∴ Positive value of E°cell favours formation of product.
Description : 6 In a two winding transformer, the primary and secondary induced emf E1 & E2 are always A. equal in magnitude B. anti phase with each other C. in phase with each other D. determined by load on transformer secondary
Last Answer : C. In phase with each other
Description : Let E1 and E2 be two entities in E-R diagram with simple single valued attributes. R1 and R2 are two relationships between E1 and E2 where R1 is one-many and R2 is many-many. R1 and R2 do not have any ... are required to represent this situation in the Relational Model? (A) 4 (B) 3 (C) 2 (D) 1
Last Answer : (B) 3
Description : There are three events E1, E2 and E3, one of which is must and only one can happen. -Maths 9th
Last Answer : Since one and only one of the three events E1, E2 and E3 can happen, i.e, they are mutually exclusive. Therefore, P(E1) + P(E2) + P(E3) = 1 ...(i) Odds against E1 are 7 : 4 ⇒ Odds in favour of E1 are 4 : 7⇒ ... \(rac{1-rac{23}{88}}{rac{23}{88}}\) = \(rac{rac{65}{88}}{rac{23}{88}}\) = 65 : 23.
Description : If the three independent events E1, E2 and E3, the probability that only E1 occurs is α, E2 occurs -Maths 9th
Last Answer : (c) 6Let \(x\), y, z be the probabilities of happening of events E1, E2 and E3 respectively. Then, \(\alpha\) = P (occurrence of E1 only) = x (1 - y) (1 - z) \(\beta\) = P (occurrence of E2 only) = (1 - \(x\)) y (1 - ... (x\) = 6z (From (i) and (ii))⇒ \(rac{x}{z}\) = 6 ⇒ \(rac{P(E_1)}{P(E_3)}\) = 6.
Description : De Broglie equation is (a) h/mv = 1 (b) E1 – E2 = hv (c) C = 1v (d) n1 = 2d sin q
Last Answer : Ans:(a)
Description : The de Broglie equation is (a) h/mv = 1 (b) hv = E2 - E1 (c) n 1 = 2d sin (d) c = hv
Description : As shown in the illustration, the circuit has been on the line for several days when component 'E1' burns out. The operator receives an alarm, switches over 'B' to energize the standby ... than required for the circuit therefore limiting the current through the alarm relay which will not pick up
Last Answer : Answer: D
Description : As shown in the illustration, what maintenance would be required of the circuit components? EL-0058 A. Change out both 'C' units monthly. B. Clean the glass surrounding 'E1' & 'E2' as needed. C. File ... upper end of 'G' every six months. D. Take megger readings on 'E1' & 'E2' windings quarterly.
Last Answer : Answer: B
Description : In a consecutive reaction system of the given figure bellow, when E1 is much greater than E2 , the yield of B increases with the (A) Increase of temperature (B) Decrease of temperature (C) Increase in initial concentration of A (D) Decrease in initial concentration of A
Last Answer : (A) Increase of temperature
Description : An atomic energy state in which more atoms are in the lower energy state E1 than in the excited state E2, is known as a) population inversion b) normal population c) stimulated population d) atomic population
Last Answer : b) normal population
Description : The emission in which the atom emits a photon of energy hf = E2 – E1 , in any arbitrary direction is a) Spontaneous emission b) stimulated emission c) induced emission d) both a & c
Last Answer : d) both a & c
Description : The incident photon absorbed by an atom in the ground state E1, thereby leaving the atom in the excited state E2 , is a) spontaneous absorption b) stimulated absorption c) induced absorption d) both b & c
Last Answer : d) both b & c
Description : Which is the most reactive alkyl halide in a SN1 reaction? (a) CH3F (b) CH3Br (c) CH3I (d) CH3Cl
Last Answer : CH3I
Description : Which of the following factors has no effect on the rate of SN1 reactions? (a) the nature of the alkyl halide (b) the nature of the leaving group (c) the concentration of the alkyl halide (d) the concentration of the nucleophile
Last Answer : the concentration of the nucleophile
Description : Which of the following compounds will undergo an SN2 reaction most readily? (a) (CH3)3CCH2I (b) (CH3)3CCl (c) (CH3)2CHI (d) (CH3)2CHCH2CH2CH2I
Last Answer : (CH3)2CHCH2CH2CH2I
Description : Which of the following species is most reactive in a SN2 reaction? (a) CH3CH2Cl (b) CH3CH2Br (c) CH3CH2I (d) CH3CH2F
Last Answer : CH3CH2I
Description : Which of the following statements concerning SN2 reactions of alkyl halides is not correct? (a) The rate of reaction depends on the concentration of the nucleophile. (b) The rate of reaction depends on the ... carbon of the C-Br bond. (d) All alkyl iodides react more rapidly than all alkyl chlorides
Last Answer : All alkyl iodides react more rapidly than all alkyl chlorides
Description : Which of the following compounds would react most rapidly in an SN2 reaction? (a) CH3CH2I (b) CH2=CH–I (c) (CH3)2CHI (d) (CH3)3CI
Description : Which compound reacts most rapidly by an SN1 mechanism? (a) Methyl chloride (b) Isopropyl chloride (c) Ethyl chloride (d) tert-Butyl chloride
Last Answer : tert-Butyl chloride
Description : SN1 reaction is having ......order. a. Zero b. First c. Second d. Third
Last Answer : b. First
Description : What happens when ethanol is heated with acidified potassium dichromate solution? Write the chemical equation.
Last Answer : Answer. Ethanol is oxidised to ethanoic acid with the help of acidified K2Cr2O7. CH3CH2OH + 2O → CH3COOH + H2O
Description : Give reason for the following: (i)alkali metals do not occur free in nature. (ii)alkali metals have low I .E. (iii)LiI is more soluble than KI in ethanol.
Last Answer : Ans.(i)They are highly reactive in natur (ii) Because of large atomic size. (III)LiI is more covalent in character than KI
Description : Which of the following statement(s) is/are true concerning carrier proteins? a. Carrier proteins are distinguished by three types of mechanisms: carrier-type, channel-type, and conduction-type b. ... and open d. Carrier-type transport proteins are equally accessible from either side of the membrane
Last Answer : Answer: b, c Most transport proteins appear to function as carriers, rather than channels. Important distinctions can be made between types of carrier proteins on the basis of transport kinetics. ... a carrier mechanism, the binding site is available only one side of the membrane at any instant
Description : The following statement(s) is/are true concerning host defense mechanisms to intraabdominal infection. a. Bacterial clearance can occur via translymphatic absorption b. Phagocytic activity and bacterial killing can ... may be walled off but are seldom sealed by the omentum and other mobile viscera
Last Answer : Answer: a, b, c The introduction of microorganisms into the normally sterile peritoneal environment invoke several potent specialized host antimicrobial defense mechanisms. Bacterial clearance, ... the contaminated enteric contents walled off, preventing continued soilage of the peritoneal cavity
Description : Consider the following statements: 1. Propagation of a nerve impulse in a myelinated nerve fibre is different from that of unmyelinated fibre. 2. The impulse actually travels by leaping through the nodes of Ranvier in an unmyelinated fibre 3. ... incorrect? (a) 1, 2 (b) 1, 3, 4 (c) 2 only (d) 2, 3
Last Answer : Ans:(d)
Description : Following acute haemorrhage, the following compensatory mechanisms occur: a. increased chemoreceptor discharge b. increased level of circulating angiotensin II c. vasoconstriction of renal efferent arterioles d. all above
Last Answer : all above
Description : What is mechanism of sn1 explain?
Last Answer : What is the answer ?
Description : Why is it easier to predict where an earthquake will occur than it is to predict when will it occur?
Last Answer : Because earthquakes tend to occur where there are stresses inthe crust which lead to the storage of energy in the form ofelastic strain. This tends to occur at plate boundaries and thisdeformation can be ... to occur in a particular area, but itdoes not enable them to say when it will occur.
Description : Which products will be obtained when lead nitrate is heated simply. Write balanced chemical equation for the reaction? State the type of chemical reaction that occur in the change. -Chemistry
Last Answer : Answer. Lead monoxide, nitrogen dioxide and oxygen gas will be liberated. It is thermal decomposition reaction.
Description : Which of the following halides is least reactive in an E2 reaction with sodium methoxide? (a) (CH3)3CCH2I (b) (CH3)2CHCHICH3 (c) (CH3)2CHCH2Br (d) (CH3)2CHCH2Cl
Last Answer : (CH3)3CCH2I
Description : Which of the following halides is most reactive in an E2 reaction with sodium methoxide? (a) (CH3)3CCH2I (b) (CH3)2CHCHICH3 (c) (CH3)2CHCH2Br (d) (CH3)2CHCH2C
Last Answer : (CH3)2CHCHICH3
Description : I know we can't predict the future, but using an educated guess, what are some things that are likely to happen in the next 10-30 years?
Last Answer : answer:If you don’t mind me stretching it to 10–40 years two things that immediately come to mind for me are: The (Technological) Singularity Event [predicted between 2040 and 2050] Attainment of biological immortality [predicted between 2035 and 2050]
Description : I spoke to a Air Force Recruiter and they said that I would be disqualified because I have 3 dependants (my wife, 2 daughters). Is there a way to get a waiver so I can join the Air Force. I would be making more money, even as an E1, than I am now.?
Last Answer : Each service is a little bit different. They usually provide a waiver but your finances and credit have to be very good. I will say that if your spouse "deserts" you or is seperated or your marriage is ... other way to do this is common law or seperate or be "deserted" as a matter of technicality.
Description : Adenylate cyclase is activated by (A) Insulin (B) Glucagon (C) Prostaglandin E1 (D) Ca2+ ions
Last Answer : Answer : B
Description : Which one of the following drugs is used in the treatment of male impotence and activates prostaglandin E1 receptors? (a) Alprostadil (b) Fluoxetine (c) Mifepristone (d) Sildenafil (e) Zafirlukast
Last Answer : Ans: A
Description : Pick out the wrong statement. (A) In process heat exchangers, saturated steam is preferred over the superheated steam (B) The maximum is the emissive power of a surface at a temperature T1 ... under natural convection conditions, the velocity profile in air, normal to the plate, exhibits a maximum
Last Answer : (B) The maximum is the emissive power of a surface at a temperature T1 occurs at a wavelength of λ1 . If the surface temperature is halved, the maximum in the emissive power would occur at a wavelength of 0.5 λ1
Description : Organic Chemistry: E2 reaction mechanism?
Last Answer : potassium tert-butoxide is a strong and exceptionally hindered base and therefore is only capable of abstracting primary (terminal) hydrogens in non-cyclic alkyl halides. The E2 mechanism is concerted, so there are no rearrangements.
Description : Which of the following statement(s) is/are true concerning the vascular response to injury? a. Vasoconstriction is an early event in the response to injury b. Vasodilatation is a ... Histamine, prostaglandin E2 (PGE2) and prostacyclin (PGI2) are important mediators of local vasoconstriction
Last Answer : Answer: a After wounding, there is transient vasoconstriction mediated by catecholamines, thromboxane, and prostaglandin F2 (PGF2a). This period of vasoconstriction lasts for only five to ten minutes. Once ... and mast cells and enhance the egress of cells and substrate into the wound and tissue
Description : The following prostanoid is a potent inducer of platelet aggregation (a) Prostacyclin (b) Prostaglandin E2 (c) Prostaglandin D2 (d) Thromboxane A2
Last Answer : Ans: D
Description : The prostanoid that consistently constricts blood vessels is (a) Prostaglandin E2 (b) Prostaglandin F2a (c) Thromboxane A2 (d) Prostacyclin
Last Answer : Ans: C
Description : Which of the following eicosanoids is generated through the lipozygenase pathway ? (a) Prostaglandin E2 (b) Thromboxane A2 (c) Prostacyclin (d) Leukotriene C4