Chemistry Questions and Answers August 13, 2020

The Lewis structures of four compounds are given. 0 PC13 CO SO CHCl2 H Which of these molecules are polar C ci,For each molecule, specify the polarity of the bonds and the overall polarity of the molecule. CI Be bonds molecule H H polar bonds molecule Answer Bank nonpolar 0 bonds molecule

The pH active salt hydrolysis reaction for NH4NO3 is O NH4 (aq) NO3(aq) NH4NO3(aq) O NH4 (aq) HO(l) H3O(aq) NH3(aq) NO3(aq) 3 HO(l) HNO3(aq) 2 H3O (aq) O NH4 (aq) HO(l) NH3(aq) H(g) OH(aq) O NO3(aq) HO(1) HNO3(aq) OH(aq)

What is the change in volume when 12 grams of H and 56 grams of N react to completion at STP. 3H2(g) N 2 NH3 O The system increases in volume by about 88 liters O The system decreases in volume by about 22 liters O The system decreases in volume by about 88 liters The system decreases in volume by about 44 liters

Asparagine is a polar amino acid, shown at pH 7. What is the maximum number of water molecules that, in theory, one asparagine molecule at pH 7 can hydrogen bond with Consider any intermolecular attractions between the asparagine molecule and water to be hydrogen bonds. number of water molecules H HNC H CH C CIO NH H 0

Predict the correct product of the following reaction. 0 OCH, 1) Ph Mg Br (excess) 2) HO Draw the molecule on the canvas by choosing buttor

The graph below represents the titration of an amino acid with NaOH solution. View the titration and answer the questions below (parts a through e). (a) At what pH are about 12 of the carboxyl groups ionized Number (b) Where does the amino acid have a net charge of 1 below pH 2.34 at pH 2.34 at pH 6.01 at pH 9.69 above pH 9.69 (c) At what point

Part A Which reaction below represents the first ionization of O O(g) e O(g) O(g) e 02(g) O(g) O(g) e O(g) O(g) e O(g) e O(g) Submit Request Answer

Part A Identify which of the following equations are balanced. Check all that apply. 2KMnO4(s)K MnO4(s) MnO2 (s) O2(g) 2KClO3(s)2KCl(s) O2(g) 6Li(s) N(g) 2Li N(s) Mg(s) N(g) Mg3N2(s) Submit Request Answer,Part A Notice that SO4 appears in two different places in this chemical equation. SO2 is a polyatomic ion called sulfate. What number

Part A Given the following proposed mechanism, predict the rate law for the overall reaction. 2NO2 Cl2 2NO2Cl (overall reaction) Mechanism NO2 Cl NOCI CI slow NO2 CI NOCl fast Rate kNOCICI Rate kNOCI Rate KNOCI Rate KNO2C112 Rate KNOC1

Given cyclohexane in a chair conformation, substitute two of the H labels with methyl and propyl to construct the more stable conformation of cis1methyl2propylcyclohexane. Use the numbering provided on the ring. 1 2 H 9 1 H H 3 H 5 H H H H H methyl propyl

Which statement related to particle and wave properties of matter is correct View Available Hint(s) Particles exhibit diffraction while waves do not. A wave travels straight through a slit. Particles interfere constructively and destructively whereas waves do not. Interference patterns are observed when a wave passes through a barrier with two

Part A The dipole moment of HF is 1.91D. What is the dipole moment of HF in C. m Express your answer in Coulombmeters to three significant figures. 1.40 10 30 Submit Hints My Answers Give Up Review Part r wwwww Incorrect Try Again 5 attempts remaining Submit Part B The distance between the atoms of HF is 0.92 . What is the distance in

Give the individual reaction orders for all substances and the overall reaction order from this rate law rate HNO4 k NO HNO24NO2 A. order of HNO2 B. order of NO C. overall order D. By what factor does the rate change if the concentration of HNO2 is doubled E. By what factor does the rate change if the concentration of NO is doubled F. By

The decomposition of HI(g) is represented by the equation 2HI(g) H(g) I(g) The following experiment was devised to determine the equilibrium constant of the reaction. HI(g) is introduced into five identical 400cm glass bulbs, and the five bulbs are maintained at 623 K.The amount of I produced over time is measured by opening each bulb and

Effective nuclear charge Number of Electrons Part D What best accounts for the periodic trends seen in ionization energy Match the items in the lefthand column with the appropriate blank in the sentences in the righthand column. The trend in accounts for the increase in ionization energy across a period. Atomic Number Principal quantum number The

PhoTe 12) Give the equation for an unsaturated solution in comparing Q with Ksp. A) Q Ksp B) Q

Part A Give approximate values for the indicated bond angles in the molecule shown. SA Express the bonding angles in degrees to four significant digits separated by a comma. 180 1,2 Submit Part B Give approximate values for the indicated bond angles in the molecule shown. Express the bonding angles in degrees to four significant digits separated

Match the 13C NMR spectrum with the compound that matches. 180 A 160 140 B OH OH 120 100 PPM 80 C 60 40 D Me 20

How many atoms are in 5.80 moles of He Select one OA. 6.02 x 1023 O B. 3.49 x 1024 O C. 4.00 O D. 1.03 x 1023 O E. none of the above

Which intermolecular force(s) do the following pairs of molecules experience Pentane 1st attempt Part 1 (1 point) pentane and pentanol Choose one or more A. London dispersion B. hydrogen bonding C. ioninduced dipole D. dipoledipole Part 2 (1 point) Pentanol See Periodic Table See Hint,Part 2 (1 point) pentanol with another molecule of pentanol

Which Lewis structure below correctly represents the compoundformed between magnesium and sulfur?

S Mg S 2 2 Mg S Mg Mg S Mg2 S none of the above

Q2 a Why do we need sampling in analogue to digital conversion b What is the condition to sample a signal correctly c If a signal is given by v(t) 5 3sin500t 1.2 cos 300mt 0.5 sin 320mt What is the minimum frequency required and what is the practical range one may choos

Infrared Spectrum Starting MaterialBenzyl Alcohol IRNIDA05226 LIQUID FILM HITNO1125 SCORE ( )SDBSNO685 BENZYL ALCOHOL 100 CHO D 4000 3000 3326 6 3088 29 3065 24 3031 10 2932 29 2875 22 1587 77 2419 84 1644 81 1962 79 1876 84 1811 81 1607 72 1593 79 1497 18 1454 7 1370 41 1332 66 1303 57 1209 23 1167 72 2000 1080 41 1039 13 1018 B 913 60 846 81 817

Propose a threestep synthetic sequence to accomplish the transformation below. 1) Br, hv 2) tBuOK 3) MCPBA 1) Br, hv 2) NaOEt 3) HBr, ROOR 1) TSCI 2) tBuOK 3) HBr, ROOR (Q), 1) Brz, hv 2) NaNH, 3) HyO 1) NaOEt 2) HBr 3) tBuok O 1) TsCl, pyr 2) NaOEt 3) HO Br OH J 8

Question 1 Question 2 Question 3 Propose a synthesis of metabromofluorobenzene starting with benzene. Br F Propose OscerSyn Synthesis 1 Propose a curved arrow mechanism for the following retro aldol reaction. OH H8 HO Propose a curved arrow mechanism for the following reaction. HC NH Create OscerSketch Answer 2 H3CNH2 Create OscerSketch Answer 3

23. What major product results from the following halogenation reaction with iodine monochloride, ICI Please note that this is a variant of Problem 24 from the Ch. 6 assigned homework. (Hint chlorine is more electronegative than iodine.) (A) (A) (B) ICI CHCl cis trans CI (B) 24. In the major product of the following bromination reaction, will

Be sure to answer all parts. The partial (valencelevel) orbital diagram for a 3 ion is shown below. 4s 3d T (3 ion) 1 out Write the symbol of the element from which this ion is derived Write the formula of the oxide this ion forms

Part A What substance would you add to NaHCO3(aq) to form a buffer solution View Available Hint(s) O NaF O NaCl O NaOH OHCIO O NH3 O HCO3 Submit Provide Feedback

From the list of list of reagents available, show how to bring about each step of this synthesis. ________________________________________ _____________________________________________

OH OH OH (5) (1) 18 64A 4 NO 1. a. Br, FeBr3 b. Cl, FeCl3 step 1 OH c. CHCHCH3, H3PO4 d. CH3CHCOCI e. CuCN step 2 NO (2) Reagents Available f. H, PdC g. HO, heat h. H3O, heat i. HPO2 j. HCOCI, AICI3 step 3 k. HNO3HSO4 1. NaNO, HCl, 0C m. SO3, HSO4 n. CH3l, OH o. CuBr step 4 step 5 OH NH OH N

Indicate whether or not each of the following structures is considered to be aromatic. A B 0 A is aromatic, B is not. B is aromatic, A is not. Both A and B are aromatic. A and B are not aromatic. WH

How many atoms of copper does the fitting contain? How many atoms of zinc does the fitting contain?

Common brass is a copper and zinc alloy containing 37.0 zinc by mass and having a density of 8.48 gcm. A fitting composed of common brass has a total volume of 114.5 cm

What is the product in the following sequence of reactions K OC(CH3) C(CH3)3 a) I b) II c) III d) IV CI Cl hu LOC(CH3)3 IV LOC(CH3)3 CI,Rank the labeled protons (HaHa) in order of increasing acidity, starting with the least acidic. OHd OH. a) Ha Hb Hc Hd b) Hb

Indicate whether the asymmetric atom in each of the following compounds has the R or S configuration. HC alanine R S OH NH cannot be determined HO OH CHUC CH R S OH malic acid H cannot be determined

O. Chem

Label each reactant and product in this reaction as a Brnsted acid or base. base acid CHOH OH CHO HO

Part A What shape would you expect for XeF4 View Available Hint(s) O O O linear bent Wh trigonal planar Tshaped trigonal pyramidal tetrahedral seesaw square planar square pyramidal trigonal bipyramidal octahedral Submit Part B ICH

Nuclear binding energies for the fusion of a mole of nuclei typically correspond to mass differences on the order of Select the correct answer below grams milligrams micrograms nanograms

Part A Which of the following trends is inversely proportional to effective nuclear charge, Zeff View Available Hint(s) Atomic size lonization energy Electron affinity All of the answers are correct. Submit

What orbitals are used to form each bond in methanol, CH3OH Be sure to answer all parts. All CH bonds are formed from C sp The CO is formed from C 3 sp 3 The OH bond is formed from O sp 0 3 H 3 sp H sp sp

Picric acid has been used in the leather industry and in etching copper. However, its laboratory use has been restricted because it dehydrates on standing and can become shock sensitive. It has an acid dissociation constant of 0.42. What is the H3O for a 0.20 M solution of picric acid A) 0.022 MB) 0.052 M C) 0.15 M D) 0.29 M E) none of the above

Question 28 The molecular geometry of the SO32 molecule is O 0 Total Domains 3 O Bonded Lone Atoms Pairs bent 2 3 linear 2 1 3 tetrahedral 2 octahedral 0 0 1 2 0 1 2 trigonal planar Molecular Shape Linear Trigonalplanar Bent Linear Tetrahedral Trigonal pyramid Bent S S. O 0

What is pKb of the conjugatebase of X-281? (Assume 25 ?C.) Express your answer numerically.

Relating pKa and pKb Learning Goal To understand the relation between the strength of an acid or a base and its pKa and pKb values. T hg degree to Which a Weak acid dissociates in solution is given by its acidion,zaon constant. K,. For the generic weak acid, HA(aq) (aq) H (aq) and the aCldionizatiO.n Constant iS given by IAIIHI Similany. the

Identify all the acidic hydrogens (pK, less than 25) in the following substances. List the acidic hydrogens by letter, example acd. HOCHCHCCCCH3 1st structure 2nd structure ab Submit Answer Try Another Version b a d CH 3 item attempts remaining Previous Next Email Instructor Save and Exit

The phase diagram for an organic compound is shown. What is the normal boiling point of this compound? Express your answer as an integer and include the appropriate units.

1.00 Pressure (atm) 0.50 0.10 150 X 75 Y 0 75 Temperature (C) Z 150

Label the energy diagram (7 bins) and indicate which reaction corresponds to the energy diagram. energy. reaction coordinate Select the reaction that matches the energy diagram. (CH,),CCI (CH),P Q (CH, CHBr NGOCHCH, OCHCHOH HICHCHIHO (CH,),CP(CH,) CH A CH,CHCH, NaBr HOCH,CH, intermediates Answer Bank AG starting materials nonlimiting

Label the intermediate(s) and transition state(s) in the reaction mechanism. Step 1 Step 2 C B First intermediate formed Second intermediate formed C First transition state formed D Second 27 transition state formed E Third transition state formed Product

a) What kind(s) of intermolecular forces exist in CHCl(1) Select all that apply. dipoledipole interactions hydrogen bonding dispersion forces b) What kind(s) of intermolecular forces exist in CH3CHCHOH(1) Select all that ap dipoledipole interactions hydrogen bonding dispersion forces D c) What kind(s) of intermolecular forces exist in HO(1)

27). How many Li atoms are contained in 97.9 g of Li (A.W, Li 6.94 ) A) 5.90x1025 Li atoms C) 8.49x1024 Li atoms E) 4.18x1024 Li atoms B) 7.09x102 Li atoms D) 4.27 x 1022 Li atoms

Hint Select the major product formed in the reaction shown below. 2 Phenylthiophene O S SnCl, CH,COC1 CH3 CH3 B CH3 HC Lo S Previous Give Up View Solution Map Check Answer Next Exit C

Match each of the following ions and molecules with its correct molecular geomet IC1 NH CIO3 BC tetrahedral trigonal pyramidal linear trigonal planar,estion 12 of 15 (1 point) Complete the Lewis structure of the chlorite ion, CIO, which is used as a bleaching agent. Complete only the two resonance structures in which the formal charges are closest

QUESTION 13 A reaction which is unfavorable with respect to entropy, but favorable with respect to enthalpy could occur at low temperatures but not at higher temperatures. could not occur regardless of temperature. could occur at any temperature. could occur at high temperatures but not at lower temperatures. none of the above 000

provide an IUPAC name for the structure shown.

Provide an IUPAC name for the structure shown. ball stick labels (Do not use stereochemical terms in you name.) Submit Answer Retry Entire Group 8 more group attempts remaining

What mass of SbF3 (molar mass 179 gmol) is needed to produce 1.00 g of Freon12, CClF (molar mass 121 gmol) 3CCI42SbF33CC1F2 SbCl3 A. 0.667 g B. 0.986 g C. 1.48 g D. 2.22 g

Review Constants Periodic Table What is the purpose of the one balloon larger in size than the other balloons to represent unoccupied space in a molecule Submit to represent any pair of electrons bonding or lone pair to represent the space lone pairs occupy in a molecule Request Answer

Match each of the following energy band structures with the type of material it represents. Show Work A B C Empty conduction band Band gap Filled valence band Empty conduction band Band gap Filled valence band Empty band Band gap Empty states Filled states Semiconductor Insulator Metal

The ________ ion is represented by the electron configuration [Ar]3d 2 V 3+ Sc 3+ Cr 3+ Mn 3+ Ti 3+

The V3 Sc3 Cr3 Mn Ti ion is represented by the electron configuration Ar3d.

Match each chemical reaction with the correct diagram according to Hess Law. Enthalpy, , , , g Enthalpy. 7 , g Enthalpy. , , B , g c g , Enthalpy. c

Print Question 14 of 14 Hint Calculator The mass spectrum of diisopropyl ether is shown below. relative abundance 100 80 Periodic Table 60 base peak 45 43 0 10 20 30 40 50 60 70 masstocharge 1. Draw the radical cation giving the molecular ion. Be sure to include the nonbonding electrons on the oxygen. 2. Identify the fragment giving rise to the

7. The reaction AB products has AG rxn 25C for this reaction. 41kJmol. Estimate a value of Keq at

1. For the reaction NO3(g) NO(g) NO(g) AG 4.78. Calculate Keq at 25C.

How much energy is required to transform 200 kg of ethyl alcohol at 20 into saturated vapor

What mass of gas would be enclosed in a tank if it is at 450 k, 150 kpa and 8 m3

What pressure will an ideal gas have subjected to 4500 Pa, 380 K and 29 m3, if its conditions were changed to 650 K and 25 m3

In what proportion does the pressure difference change in a duct that reduces its radius by half if it is desired to keep the flow rate Q constant

A 10 cm3 sample of an unknown gas diffuses in twice the time that 10 cm3 of HBr gas diffuses. What is the molar mass of the unknown gas

When adding NaI and Acetone what products do you end up with for each of the substrates ? 1-Chlorobutane 2-Chlorobutane 2-Bromobutane t-butyl-Chloride (2-Chloro-2-methyl propane) Benzyl Chloride Bromobenzene

Find out the collision frequency of CO2 having cross-section 0.52nm^2 with relative speed 536m/s ? (Temperature=298K and Pressure= 12atm)

Naturally occurring chlorine is 75.53 C135 which has an atomic mass of 34.969 amu and 24.47 C17 which has a mass of 36.966 amu. Calculate the average atomic mass of chlorine (a) 35.5 amu (b) 36.5 amu (c) 71 amu (d) 72 amu

2. How many carbon atoms are present in 0.35 mol of C6H2O6 (a) 6.023 1023 carbon atoms (c) 1.26 x 1024 carbon atoms (b) 1.26 x 1023 carbon atoms (d) 6.023 1024 carbon atoms

3. A Calculate the mass in gm of 2N molecules of CO (c) 88 gm (a) 22 gm (b) 44 gm (d) None of these.

The density of O at 0C and 1 atm is 1.429g litre. The molar volume of gas is (a) 22.4 lit. (b) 11.2 lit (c) 33.6 lit (d) 5.6 lit.

How many molecules are in 5.23 gm of glucose (C6H2O6) (a) 1.65 x 102 (b) 1.75 1022 (c) 1.75 x 101 (d) None of these

What is the weight of 3.01 1023 molecules of ammonia (c) 34 gm (a) 17 gm (b) 8.5 gm (d) None of these

Which is heaviest (a) 25 g of Hg (b) 2 mole of HO (c) 2 mole of CO (d) 4 gatom of O

16 g of SO, occupies 5.6 litre at STP. Assuming ideal gas nature, The value of x is (a) 1 (b) 2 (c) 3 (d) None of these

The density of liquid (mol. wt. 70) is 1.2 g mL. If 2 mL of liquid contains 35 drops, the number of molecules of liquid in one drop are (a) 1.2 3.5 N A (b) 1 35 N A (c) 1.2 35 N A (d) 1.2 NA

How many moles of magnesium phosphate Mg3(PO4)2 will contain 0.25 mole of oxygen atoms (b) 3.125 x10 (c) 1.25 x10 (d) 2.5 10 (a) 0.02

Rearrange the following (I to IV) in the order of increasing masses. (I) 0.5 mole of 03 (III) 3.011 1023 molecules of 0 (a) IV III II

The percentage by mole of NO in a mixture of NO(g) and NO(g) having average molecular mass 34 is (a) 25 (b) 20 (c) 40 (d) 75

An iodized salt contains 0.5 of Nal. A person consumes 3 gm of salt everyday. The number of iodide ions going into his body everyday is (a) 104 (b) 6.02 104 (c) 6.02 1019 (d) 6.02 x 1023

The number of carbon atoms present in a signature, if a signature written by carbon pencil weights 1.2 10 g is (a) 12.04 x 1020 (b) 6.02 x 1019 (c) 3.01 1019 (d) 6.02 1020

An unknown compound contains 8 sulphur by mass. Calculate Least molecular weight of the compound (a) 200 (b) 300 (c) 400 (d) 1200

The haemoglobin from the red blood corpuscles of most mammals contains approximately 0.33 of iron by weight. The molecular weight of haemoglobin as 67,200. The number of iron atoms in each molecule of haemoglobin is (atomic weight of iron 56) (a) 2 (b) 3 (c) 4 (d) 5

Insulin contains 3.4 sulphur. The minimum molecular weight of insulin is (a) 941.176 (b) 944 (c) 945.27 (d) None of these

2.76 g of silver carbonate on being strongly heated yields a residue weighting (a) 2.16 g (d) 2.64 g (b) 2.48 g (c) 2.32 g

How many gram of KCl would have to be dissolved in 60 g HO to give 20 by weight of solution (a) 15 g (c) 11.5 g (b) 1.5 g (d) 31.5 g

Density of 2.05 M solution of acetic acid in water is 1.02 gmL. The molality of same solution is (a) 1.14 mol kg1 (b) 3.28 mol kg (c) 2.28 mol kg1 (d) 0.44 mol kg

Match the column Column I (A) 16 g (B) (C) 22 g (D) 9 g of HO (a) AQ BP,R CP,R DP (c) AQ BR,S CP,R DP 1 g of CH4 of H of CO (P) (Q) (R) (S) Column II 1 mole molecule 6.023 1023 5 atoms 11.2 litre 1.806 1023 atoms (b) AP BP,R CR DS (d) AR BP,R CR,S DQ

Flourine reacts with uranium to produce uranium hexafluoride, UF, as represented by this equation U(s) 3F(g) UF (g) How many fluorine molecules are required to produce 2.0 mg of uranium hexafluoride, UF 6, from an excess of uranium The molar mass of UF is 352 gmmol. (a) 1.0 1020 (b) 1.0 1019 (c) 1.0 1021 (d) 1.0 1022

Two substance P4 O are allowed to react completely to form mixture of P406 P4010 leaving none of the reactants. Using this information calculate the composition of final mixture when mentioned amount of P4 O are taken.,P406 P4010 P430 P450 If 1 mole P4 4 mole of O are taken (a) 0.5, 0.5 (b) 2,1 (c) 1, 2 (d) 1, 1

How many years it would take to spend Avogadros number of rupees at the rate of 1 million rupees in one second (a) 19.098 x 109 years (c) 19.098 x 10 years (b) 19.098 years (d) None of these

Calculate the number of Cl and Cat2 ions in 222 g anhydrous CaCl. (a) 2N ions of Ca2 4 N ions of Cl (c) IN ions of Cat2 1N ions of Cl (b) 2N ions of Cl 4N ions of Ca (d) None of these.

A hydrate of iron (III) thiocyanate Fe(SCN)3, was found to contain 19 HO. What is the formula of the hydrate (a) Fe(SCN)3.3HO (b) Fe(SCN)3.2HO (c) Fe(SCN)3.HO (d) Fe(SCN).2HO

How many molecules are present in 1ml of water vapours at 0C and 1 atm (a) 1.69 10 (b) 2.69 x 1019 (c) 1.69 x 1019 (d) 2.69 1019

Calculate the weight of lime (CaO) obtained by heating 200 kg of 95 pure lime stone (CaCO3). (a) 104.4 kg (b) 105.4 kg (c) 212.8 kg (d) 106.4 kg

A mixture of FeO and Fe3O4 when heated in air to constant weight gains 5 in its weight. Find out composition of mixture. (a) FeO 20.28, Fe3O4 79.72 (c) FeO 36.36, Fe3O4 63.64 (b) FeO 79.72, Fe3O4 20.28 (d) FeO 63.64, Fe3O4 36.36

8g of sulphur are burnt to from SO2, which is oxidised by Cl water. The solution is treated with BaCl solution. The amount of BaSO4 precipitated is (a) 1.0 mole (b) 0.5 mole (c) 0.75 mole (d) 0.25 mole

8 litre of H and 6 litre of Cl are allowed to react to maximum possible extent. Find out the final volume of reaction mixture. Suppose P and T remains constant throughout the course of reaction (a) 7 litre (c) 2 litre (b) 14 litre (d) None of these.

At high temperatures, the compound S4N decomposes completely into N and sulphur vapours. If all measurements are made under the same conditions of temperature and pressure, it is found that for each volume of SN decomposed 2.5 volumes of gaseous products are formed. What is the molecular formula of sulphur (b) S (c) S4 (a) Sg (d) S

A mixture of formic acid and oxalic acid is heated with concentrated HSO4. The gas produced is collected and on its treatment with KOH solution the volume of the gas decreased by onesixth. Calculate the molar ratio of the two acids in the original mixture. (a) 41 (b) 14 (c) 23 (d) 32

How much ammonia will be formed from 2.95 g of acetamide at STP CH3CONH NaOH CH3COONa NH3 (b) 2240 ml (a) 1120 ml (c) 4000 ml (d) 4200 ml