Chemistry concepts and calculations

Which of the following is not used to alter the activity of enzymes through cova

Which of the following is not used to alter the activity of enzymes through covalent modification? a. Phosphorylation. b. Methylation. c. ADP-ribosylation. d. Uridylyllation. e. C…

Which of the following is not usually considered a controlled trial? (As in FDA’

Which of the following is not usually considered a controlled trial? (As in FDA’s definition of an “adequate and well controlled trial”?) a. Comparison of drug treated group to a …

Which of the following is often true of the active site of an enzyme? Question 2

Which of the following is often true of the active site of an enzyme? Question 22 options: it consists of the N-terminal and C-terminal amino acids it consists of amino acids whic…

Which of the following is only an electron withdrawing group 19. An unknown comp

Which of the following is only an electron withdrawing group 19. An unknown compound has the formula C8H10OS, and is known to contain a thiophene ring. The proton NMR spectrum of …

Which of the following is present in the flask after some NaOH has been added to

Which of the following is present in the flask after some NaOH has been added to the ethanoic acid, but before the equivalence point has been reached. Explain your answers careful…

Which of the following is produced by chemical weathering? Select one: dissolved

Which of the following is produced by chemical weathering? Select one: dissolved silica dissolved iron oxide dissolved calcium carbonate all of the above Why are members of the cl…

Which of the following is rate determining step in electrophilic substitution re

Which of the following is rate determining step in electrophilic substitution reaction? a) Generation of electrophile b) Attack by an electrophilic reagent on benzene ring c) Form…

Which of the following is the BEST description of thesolvation of an ionic compo

Which of the following is the BEST description of thesolvation of an ionic compound? a. particles of a solid are mixed into a heterogeneous mixtureby stirring in water. b. polar w…

Which of the following is the IUPAC name for the following compound? A. (S)-2-pe

Which of the following is the IUPAC name for the following compound? A. (S)-2-pentanol (S)-2-butanol (R)-2-pentanol (R)-2-butano Which of the following strategies will NOT be an e…

Which of the following is the best definition of atomic mass? The average mass o

Which of the following is the best definition of atomic mass? The average mass of the atoms of an element compared to the mass of an atom of carbon-12 at exactly 12 atomic mass un…

Which of the following is the best description of a chaperone An enzyme that cat

Which of the following is the best description of a chaperone An enzyme that catalyzes hydrolysis of chaperonins A simple molecule that associates to antigen A carbohydrate that c…

Which of the following is the best description of the mechanism of the reaction

Which of the following is the best description of the mechanism of the reaction between a ketone and an amine to form an imine? Answer a. nucleophilic addition followed by elimina…

Which of the following is the best nucleophile in __________? Which of the follo

Which of the following is the best nucleophile in __________? Which of the following is the best nucleophile in water? CH3S Submit Answer Tries 0/1 Which of the following is the b…

Which of the following is the best reason as to why the strands of a DNA molecul

Which of the following is the best reason as to why the strands of a DNA molecule are more easily separated at pH > 11? A) At pH 11 the cross-strand negative charge repulsion b…

Which of the following is the best reason as to why the strands of a DNA molecul

Which of the following is the best reason as to why the strands of a DNA molecule are more easily separated at pH > 11? A) At pH 11 the cross-strand negative charge repulsion b…

Which of the following is the best reducing agent? A) Ni^2+ B) Ni C)Zn D)Ag Ni^2

Which of the following is the best reducing agent? A) Ni^2+ B) Ni C)Zn D)Ag Ni^2+ (aq) + 2e^- rightarrow Ni(s) -0.23V Zn^2+(aq) + 2e^- rightarrow Zn (s) -0.76 V Ag^+ (aq) + e^- ri…

Which of the following is the conjugate acid of the biphosphate ion (HPO_4^2-)?

Which of the following is the conjugate acid of the biphosphate ion (HPO_4^2-)? a.) H_3PO_4 b.) H_2 PO_4^- c.) HPO_4^2- d.) PO_4^3- Which of the following is the most ideal condit…

Which of the following is the correct IUPAC name for the compound (a) 4-trydroxy

Which of the following is the correct IUPAC name for the compound (a) 4-trydroxy - 3 methyl-hexanoic acid (B) 3-hydroxy-2-ethyl-pentanoic acid (C) 3-methyl-4-hydroxy-peentyl carbo…

Which of the following is the correct chemical symbol for Potassium A) K B) Po C

Which of the following is the correct chemical symbol for Potassium A) K B) Po C) Pu D) P Which of the following is an incorrect chemical symbol A) Ti B) SN C) Ti D) Zn Which of t…

Which of the following is the correct definition for a pair of enantiomers? A pa

Which of the following is the correct definition for a pair of enantiomers? A pair of stereoisomers that are not mirror images of each other. A pair of stereoisomers that have a p…

Which of the following is the correct definition for effusion? gas molecules mix

Which of the following is the correct definition for effusion? gas molecules mix unequally gas molecules mix equally gas molecules spread out in a concentration gradient gas molec…

Which of the following is the correct definition of a Lewis acid? A Lewis acid i

Which of the following is the correct definition of a Lewis acid? A Lewis acid is an electron pair donor A Lewis acid dissociates to give protons A Lewis acid is an electron pair …

Which of the following is the correct definition of a Lewis acid? A Lewis acid i

Which of the following is the correct definition of a Lewis acid? A Lewis acid is an electron pair donor A Lewis acid dissociates to give protons A Lewis acid is an electron pair …

Which of the following is the correct equilibrium expression for the reaction of

Which of the following is the correct equilibrium expression for the reaction of a weak base with water? A.           *O H-   +   H2O         *OH2    + OH-             B.         …

Which of the following is the correct example of one of thefive forms of energy?

Which of the following is the correct example of one of thefive forms of energy?       Sound waves are a form of radiantenergy.        Infrared radiation is anexample of radiant e…

Which of the following is the correct formula for potassium diaquatetrachloromol

Which of the following is the correct formula for potassium diaquatetrachloromolybdate (III)? Which of the following compounds can exhibit optical activity? Two platinum complexes…

Which of the following is the correct order of bond strength going from stronges

Which of the following is the correct order of bond strength going from strongest to weakest? Ionic> Hydrogen> Covalent> Van der Waals Ionic> Covalent> Hydrogen>…

Which of the following is the correct order of bond strength going from stronges

Which of the following is the correct order of bond strength going from strongest to weakest? Ionic> Hydrogen> Covalent> Van der Waals Ionic> Covalent> Hydrogen>…

Which of the following is the correct order of decreasing acid strength (more ac

Which of the following is the correct order of decreasing acid strength (more acidic > less acidic)? Answer a. FCH2COOH > CH3COOH > CH3OH b. CH3COOH > ClCH2COOH > C…

Which of the following is the correct order of decreasing basicity (stronger bas

Which of the following is the correct order of decreasing basicity (stronger base > weaker base)? A. CH3COONa > NaOH > NaOMe > NaNMe2 B. MeNH2 > NH3 > MeOH > …

Which of the following is the correct rate law? a. Rate-k[ITHAsoH\'y b. Rate-k[I

Which of the following is the correct rate law? a. Rate-k[ITHAsoH'y b. Rate-k[IHAso Rate-kIITPIHAsoPHT e. series of kinetic measurements are made on the decomposition of a reactan…

Which of the following is the correct reaction for the complete hydrolysis of th

Which of the following is the correct reaction for the complete hydrolysis of this compound, lets just call it Glycopeptide X. Use the following tri-peptide: Asp-Ser-Phe and that …

Which of the following is the definition of a buffer? an organic compound which

Which of the following is the definition of a buffer? an organic compound which is only soluble in an organic solvent a substance that catalyzes a reaction a solution containing a…

Which of the following is the definition of gradient elution? In a gradient elut

Which of the following is the definition of gradient elution? In a gradient elution, the solvent composition is held constant throughout the elution. In a gradient elution, the ap…

Which of the following is the definition of saponification? A. hydrolysis of an

Which of the following is the definition of saponification? A. hydrolysis of an ester in a basic solution B. hydrolysis of an ester in an acidic solution C. hydrolysis of a fatty …

Which of the following is the definition of spectral interference in plasma and

Which of the following is the definition of spectral interference in plasma and flame atomic emission spectrometry? A spectral interference in atomic spectroscopy occurs when a sp…

Which of the following is the electron dot formula for an atom of carbon? A) (a)

Which of the following is the electron dot formula for an atom of carbon? A) (a) B) (b) C) (c) D) (d) E) (e) Which of the following elements has the lowest ionization energy? A) 1…

Which of the following is the formation reaction for CH 3 OH(l)? Answer C(s, gra

Which of the following is the formation reaction for CH3OH(l)? Answer C(s, graphite) + 2 H2(g) + 1/2 O2(g) ? CH3OH(l) C(s, graphite) + 4 H(g) + O(g) ? CH3OH(l) 2 C(s, graphite) + …

Which of the following is the intermediate for halogenation conditions? An enola

Which of the following is the intermediate for halogenation conditions? An enolate An enolate A tautomer An epimer The reaction below is a direct enolatc alkylation It has been fo…

Which of the following is the least acidic? dihydrogen phosphate ion (pKa = 7.21

Which of the following is the least acidic? dihydrogen phosphate ion (pKa = 7.21) water (pKa = 15.74) actetic acid (pKa = 4.76) hydrochloric acid (pKa = -7.0) A) dihydrogen phosph…

Which of the following is the minor resonance contributor of a ketone? Which of

Which of the following is the minor resonance contributor of a ketone? Which of the following correctly lists the formal charges on each atom of nitro methane (the tow oxy gens ar…

Which of the following is the minor resonance contributor of a ketone? Which of

Which of the following is the minor resonance contributor of a ketone? Which of the following correctly lists the formal charges on each atom of nitro methane (the tow oxy gens ar…

Which of the following is the monomer for cellulose? (A) alpha-D-glucose (B) bet

Which of the following is the monomer for cellulose? (A) alpha-D-glucose (B) beta-D-glucose (C) chitin (D) amylase (E) None Which amino acid does not have a chirality center? (A) …

Which of the following is the most acidic: HBrO_2, HFO_2, HIO_2, and HCIO_3? HBr

Which of the following is the most acidic: HBrO_2, HFO_2, HIO_2, and HCIO_3? HBrO_2 HFO_2 HIO_2 HCIO_3 Which of the following is considered a Lewis acid? CH_2NH_2 BCI_3 F BF_4 CH_…

Which of the following is the most appropriate procedure to make a 1.00 L of 0.1

Which of the following is the most appropriate procedure to make a 1.00 L of 0.150 M sodium solution? Add 0.150 mol sodium chloride to a one liter volumetric flask and dilute to a…

Which of the following is the most effective buffer system for a pH value of 4.4

Which of the following is the most effective buffer system for a pH value of 4.45? H2CO3/HCO3–     (Ka1 for H2CO3 is 4.3 × 10–7.) HCO3–/CO32–     (Ka2 for H2CO3 is 4.8 × 10–11.) H…

Which of the following is the most insoluble in water? Answer Li 2 CO 3 NaOH Mg(

Which of the following is the most insoluble in water? Answer Li2CO3   NaOH Mg(OH)2 Ba(OH)2 Which of the following is the most soluble in water? Answer   Pb(NO3)2 BaSO4 AgCl CaSO4…

Which of the following is the most plausible explanation for the fact that the s

Which of the following is the most plausible explanation for the fact that the saponification of the triacylglycerol in the passage resulted in four different fatty acid salts? ti…

Which of the following is the most reactive substrate in an E2 reaction CH_3Br C

Which of the following is the most reactive substrate in an E2 reaction CH_3Br CH_3CH_2CH_2CH_2Br CH_3CH(Br)CH_2CH_3 (CH_3)_3CBr I II III IV Which of the following statements abou…

Which of the following is the most stable alkene? Which of the following will gi

Which of the following is the most stable alkene? Which of the following will give the highest percentage of elimination when treated with NaOCH_2CH_3 in ethanol? A) CH3CH2 Br B) …