Chemistry Questions and Answers August 23, 2020

1. Which one of the following is NOT a mass analyzer (3 points) (A) Quadrupole, (B) Doublefocusing analyzer, (C) Electrostatic sector analyzer, (D) TOF, (E) All above are mass analyzers. 2. What is the major component in the torch of ICPMS (A) Methane (B) Hydrogen (C) Oxygen (D) Argon (E) Nitrogen. 3. Which of the following is the most suitable to

How many signals would be expected in NMR spectrum of Br-CH2-CH2-Br A)4 B)8 C)1 D)2

Select the azo dye : A) Indigo B) Methyl orange C) Malachite green D) phenolphthalein

The heat change in at constant pressure is ) ) C) V D) a chemical reaction

Which of the following decays takes place in phosphorescence ? A) S1 S0 B) T1 S0 C) T2 T1 D) S2 S1

Drug which lower the body temperature in feverish are called : A) Antibiotic B) Analgesics C) Antipyretics D) antimalarials

Metal present in vitamin B12 is : A) Zn B) Cu C) Mg D) Co

The combustible material on the tip of safety match stick is : A) Antimony phosphate B) Antimony sulphide C) Lead nitrite D) Lead phosphate

Nitrolim is : A) CaCN2 B) Ca(NO3)2 C) Ca(CN)2 D) CaCN2 and C

Which of the following hydride is electron deficient molecules? A) C2H6 B) NaH C) B2H6 D) None of the above

Cryolite is chemically : A) Sodium aluminium fluoride B) Magnesium silicate C) Calcium magnesium carbonate D) Sodium borofluoride

The site of oxidation in an electrochemical cell is : A) Cathode B) Anode C) Solvent D) None

A first order reaction requires 12 months for the concentration of the reactant to be reduced to 25% its original value. Its half life is : A) 6 months B) 12 months C) 18 months D) 24 months

Which is more effective in coagulating a negative solution? A) Na+ B) Ba2+ C) Al3+ D) All same

The phase rule can be expressed mathematically as : A) F+P=C+2 B) F=C-P+2 C) P=C-F+2 D) All

The first organic compound synthesized in the laboratory is : A) Urea B) Lactic acid C) Vitamin A D) Cane suga

Tetra ethyl lead is used as : A) Fire extinguisher B) Pain killer C) Lubricating oil D) Petroleum additive

At triple point : A) Only the temperature is fixed B) Only pressure is fixed C) Both temperature and pressure are fixed D) none

A system with zero degree of freedom is known as : A) Invarient B) Bivarient C) Monovarient D) none

Liquid crystals have : A) Properties of a super cooled liquid B) Properties of amorphous solids C) The fluidity of a liquid and optical properties of a solid D) None of these

Indicator used in the titration between oxalic acid and NaOH is : A) Methyl orange B) Diphenyl amine C) KMnO4 D) phenolphthalein

Ionic strength of 0.20 molal KCl is: A) 0.40 B) 0.20 C) 0.85 D) 0.75

The work done during the expansion of 1 mole of an ideal gas against a constant external pressure of 1 atm from a volume of 10dm3to a volume of 30dm3 is : A) 80 dm3 atm B) 40 dm3 atm C) 20 dm3 atm D) 60 dm3 atm

The expression for energy of the particle in a one dimensional box is: A) n 2h 2 /8ma2 B) n 2 /8hm2a 2 C) nh/4m2a 2 D) n 2h 2 /4m2a 3

What is Saytzeff's rule? Explain with an example?

Cyclo alkanes have the general formula : A) CnH2n+2 B) CnH2n C) CnH2n-2 D) CnH2n-6

CH3 C CH and CH3CH2C CH are A) Structural isomer B) Tautomers C) Homologoues D) Optical isomer

The CC bond length in alkane is A) 1.54 A B) 1.65 A C) 1.26 A D) 1.33 A

Benzene can be directly converted to toluene by : A) Wurtz reaction B) Friedel Crafts reaction C) Kolbe reaction D) None of these C6H6+CH3Cl+AlCl3 C6H5-CH3

Acid catalyzed dehydration of alcohols takes place through : A) Carbocation intermediate B) Carbanion intermediate C) Carbene intermediate D) Free radical intermediate

Electrophiles are : A) Negatively charged particles B) Lewis bases C) Lewis acids D) May be Lewis acids or Lewis bases

In Lassaignes test for nitrogen, the blue colour is due to the formation of A) Ferric ferrocynide B) Potassium ferrocynide C) Sodium ferrocynide D) Sodium cynide

Chlorine present in an organic compound can be estimated by: A) Dumas method B) Victor Mayer's method C) Carius method D) None of these

Lyman series of lines in hydrogen spectrum is formed during the transaction of electrons from high levels to A) First orbit B) Second orbit C) Third orbit D) Fourth orbit

The reaction used to prepare acetoacetic ester from ethyl acetate is known as : A) Michal addition B) Claisen condensation C) Cannizaro reaction D) Claisen-smidth reaction

The wave number of a radiation having wavelength 4000A. is A) 25000cm1 B) 2500 cm1 C) 6000 cm1 D) 40000 cm1

Ziesels method is used to estimate group in organic compounds. A) Alcoholic B) Amino C) Carboxyl D) alkoxy

An inverse spinel from the following is : A) Mn3O4 B) Fe3O4 C) Al2O3 D) Co2O3

What type of colloid is milk A) Foam B) Gel C) Emulsion D) Solution

Which is a molecular crystal A) graphite B) Ice C) Aluminium D) Sodium chloride

87) Two wave function on and om are orthogonal if A) S yn ym dz1 B) J yn ym dz0 C) Syn pm dz1 D) Syn ym dz0

The solubility of a gas is 0.890 /L at a pressure of 121 kPa. What is the solubility of the gas if the pressure is increased to 101 kPa, given that the temperature is held constant?

The thermal decomposition of phosphine (PH3) into elemental phosphorus and molecular hydrogen occurs via first-order kinetics. At a temperature of 680C the half-life for this process is 35.0 seconds. If the initial concentration of the PH3 is 0.475 M, then what concentration of PH3 will remain after an elapsed time of 2.00 minutes? 4 PH3 (g) P4

For the reaction 2 NO2(g) N2O4 (g), Hrxn = -58.0 kJ/mol and S = -176.6 J/Kmol. Calculate G and the equilibrium constant K.

Identify all the possible products. Ph Ph too CHCl3 KO

What is in your bucket if you initially combine 25 mL of a 0.25 M HF solution and 25 mL of a 0.125 M KOH solution and then add 50 mL of 0.25 M NaOH. a) OH- and F- b) KOH c) HF and F- d) HF e) NaOH

A hydrogen atom in its ground state is irradiated by the light of wavelength 970 . Taking hc / e = 1.237 10-6 eV m and the ground state energy of hydrogen atom as -13.6eV the number of lines present in the emission spectrum is.

Consider a hydrogen atom with its electron in the nth orbital. Electromagnetic radiation of wavelength 90 nm is used to ionize the atom. If the kinetic energy of the ejected electron is 10.4 eV, then the value of n is (hc = 1242 eV nm).

The atomic masses of He and Ne are 4 and 20 amu respectively. The value of the de Broglie wavelength of He gas at -73oC is M times that of the de Broglie wavelength of Ne at 727oC M is.

Not considering the electronic spin, the degeneracy of the second excited state (n = 3) of the H atom is 9, while the degeneracy of the second excited state of H is.

What is the molar mass of citric acid (H3C6H5O7)? a. 192.12 g/mol b. 189.10 g/mol c. 132.07 g/mol d. 29.02 g/mol e. 89.07 g/mol

How many molecules are in 30.1 g of sulfur dioxide a. 1.81 x 105 b. 2.83 x 1023 c. 6.02 x 1023 d. 1.02 x 1024 e. 5.00 x 1023

How many moles of hydrogen are there in 6.50g of ammonia (NH3) a. 0.382 mol b. 1.39 mol c. 0.215 mol d. 1.14 mol e. 2.66 mol

What are the stoichiometric coefficients in the following equation when it is balanced SiCl4(s) H2O(1) H2SiO3(s) HCl(g) a. 1,3,1,3 b. 1,1,3,4 c. 1,4,1,4 d. 1,3,1,4 e. 3,9,1,4

Ammonia is produced by the reaction of nitrogen and hydrogen N2(g) H2(g) NH3(g) (a) Balance the chemical equation. (b) Calculate the mass of ammonia produced when 35.0g of nitrogen reacts with hydrogen.

What is the molarity of a HCl solution, if 28.6 mL of a 0.175 m NaOH solution is needed to neutralize a 25.0 mL sample of the HCl solution?

What is the pressure of 0.905 atm in units of mm Hg?

What is the final volume (in mL) of a balloon that was initially 500.0 mL at 25 C and was then heated to 50 C

A sample of helium gas initially at 37.0 C, 785 torr and 2.00 L was heated to 58.0 C while the volume expanded to 3.24 L. What is the final pressure in atm

How many moles of gas were added to a balloon that started with 2.3 moles of gas and a volume of 1.4 L given that the final volume was 7.2 L

If a mixture of gases contained 78 nitrogen at a pressure of 984 torr and 22 carbon dioxide at 345 torr, what is the total pressure of the system

A highprotein diet contains 72.0g of carbohydrate, 6.0g of fat, and 160g of protein. How much energy, in kilocalories, does the diet provide (round to the nearest tens place).

How many kilocalories are lost when 580g of water cools from 67C to 22C

In a freezer, 160g of water at 0C is placed in an ice cube tray. How much heat, in kilocalories, must be removed to form ice cubes at 0C

Show the reaction of organic compounds with some oxidising or reducing agents.What are the products formed?

Show examples for witting,grignard,Duels alder,Robinson annelation, aldol reaction etc.Which reagents are used in each and what are the products formed?

The titration of 80.0 mL of an unknown concentration H3PO4 solution requires 126 mL of 0.218 M KOH solution. What is the concentration of the H3PO4 solution (in M) according to the equation below 2265 to gninniged siis dmavol ysbaanbsW no sub zi siup HPO4(aq) 3 KOH(aq) 3 HO()KPO4(q) 1201 1 1 1 1

The Lewis structure for Te has a total of dots b. The Lewis structure for Ga has a total of dots are unpaired. dots are unpaired. c. The Lewis structure for Mg2 has a total of are unpaired. 0.6 pts dots, of these dots, of these dots, of these

Magnesium has three known isotopes with the following atomic masses and percent abundances: Isotope Abundance (%) Atomic Mass Mg - 24 78.70 23.985 Mg - 25 10.13 24.986 Mg - 26 11.17 25.983 Calculate the average atomic mass of Magnesium.

For the acidbase reaction below, calculate the mass (in grams) of HNO3(aq) necessary to ne zerbua) ganotul silho completely neutralize 4.85 g of Ca(OH)(aq). on navin ton avari bas ton 2 HNO3(aq) Ca(OH)2(aq) 2 HO() Ca(NO3)2(aq) bola tanollont nata 1

Which of the following combinations of quantum numbers cannot exist Circle your answer choice. a) n 4, 12, m 2, m, 2 b) n 3, 12, mi 2, ms 0 c) n 3, 13, m 1, m, d) n 2, 10, m0, ms can exist cannot exist can exist cannot exist can exist cannot exist can exist cannot exist

Calculate the hydronium ion concentration in an aqueous solution with a pH of 2.33 at 25C. 2.1 x 1010 M 9.7 x 1010 M 4.7 x 103M 3.8 x 105 M 6.3 x 106 M

If 48.9 g of NO and 26.9 g of 0 react together, what is the mass in grams of NO that can be formed via the reaction below 2 NO (g) O (g) 2 NO (g) 1 4 7 2 5 8 77.3 g 3 6 96 0 Submit X C x 100

A gas expands from a volume of 3.58 L to 8.64 L under a constant external pressure of 1.22 atm. How much work is done on the gas in joules Give the value to three significant figures.

Briefly describe the types of Stereoisomers.

Give the difference between Stereospecific and Stereoselective Reactions.

Predict the missing component in the nuclear equation. 207 Pb X e 82 207 TI 81 B 207 Bi 83 .C 207 Pb 82

Which expression corresponds to the equilibrium constant Kc for the reaction written as 2NH3(g) 20(g) NO(g) 3HO(g) O NH,O, N,OH,O,J O N,OH,O, NH0 O N0H01 1 NH 0 O 3N0H01 4NH0 Goose

What is the wavelength (in nm) of a photon if the energy is 6.10 x 1019 J (h 6.626 x 1034 J. s) 1 4 7 3.26 x 10 16 2 5 8 9 3 6 690 nm C x 100

Convert 8.8 km to miles.

Reaction I is a REDOX reaction because there is a clear transfer of electrons occurring between the two reactants. A. Label each compound from the reaction above in the spaces provided. Oxidizing Agent Reducing Agent becomes Oxidized. becomes Reduced. B. Overall, in reaction 1 above, electrons from compound compound resulting in the. Below are the

the pictures are in order. Please answer all questions, thx

PART 2 REDUCTION AND OXIDATION REACTIONS REDOX reactions will be a big part of our metabolic unit in this course. You will need to be able to identify if a reaction is a REDOX reaction based on the compounds in the reactants. REDOX Reduction (or the gaining of an electron) REDOX Oxidation (or the loss of an electron) In the scope of BIS2A, we

The lines in the microwave spectrum of H 27I are separated by A cm. The lines in the microwave spectrum of 2H 271 will be separated by a) A4 b) A2 c) A2 d) A

The moment of inertia for HCI gas can be determined from its microwave spectrum. Which property of the HCI molecule may be obtained from the moment of inertia a) The vibrational frequency b) the force constant c) the bond strength d) the bond length.

Calculate the spacing between the rotational lines of DF if spacing between rotational lines HF is 40 cm a) 20 cm b) 60 cm c) 30 cm d) 7.5 cm

What will be the theoretical number of vibrational degrees of freedom in benzene, carbon dioxide and sulphurdioxide respectively (a) 12, 4, 3 (c) 30, 4, 3 (b) 3, 4, 12 (d) 30, 3, 3

Predict the number of translational, rotational and vibrational degree of freedom in Neon (a) 3, 0, 0 (b) 3, 1,0 (c) 3,0, 1 (d) 3, 1, 1

The magnitude of the nuclear spin angular momentum of a nuclei 152 units. The value of I is a) 52 b) 12 c) 1 d) 32

The most populated rotational state for HCI (B 8.5 cm) at 300 K is a) 2 b) 3 c) 4 d) 7

The molecular formula of a compound is XY,. If this molecule shows three Infrared bands, speculate the structure of the molecule (a) Bent (b) Linear (c) Bent or linear (d) None of these

The equilibrium position ratio (nn) of a doubly degenerate energy level (E.) lying at energy 2 units higher than a lower nondegenerate energy level (E) assuming k T 1 unit, will be (a) 2e (b) 2e (c) e (d) e2

If the reduced mass of a diatomic molecule is doubled without changing its force constant, the vibrational frequency of the molecule will be (a) 2 times the original frequency (c) twice the original frequency 1 (b) 2 (d) unchanged times the vibrational frequency

Vibrations of diatomic molecule are usually modelled by a harmonic potential. If the potential is given by x, the correct statement is a) force is 2x and force constant is 2 c) force is 2x and force constant is 1 b) force is 2x and force constant is 2 d) force is 2x and force constant is 1

The rotational constant and the fundamental vibrational frequency of HBr are, respectively, 10 cm and 2000 cm. The corresponding values for DBr approximately are b) 10 cm and 1410 cm a) 20 cm and 2000 cm c) 5 cm and 2000 cm d) 5 cm and 1410 cm

Which of the following molecule is not spherical rotar a) CH CI c) CCI b) CHCl d) CHCI,

The following data were obtained from the vibrational fine structure in the vibronic spectrum of a diatomic molecule w512 cm, w x 8cm Where w is the energy associated with the natural frequency of vibration and x is the anharmonicity constant. The dissociation energy (D) of the molecule is (in cm)

The angle between the planes (100) and (110) is a) 30 c) 45 b) more than 30 but less than 45 d) more than 45

Calculate the lattice energy of KCI at 298 K. Given that Sublimation Energy of K(s) 89 kJ mol lonization energy of K(g) 418 kJ mot Dissociation energy of Cl(g) 244 kJ mol Electron attachment energy of Cl(g) 349 kJ mol Formation of KCI(s) 437 a) 575 kJ mol b) 202 kJ mol c) 717 kJ mol d) 800 kJ mol

P, F and I represent primitive, facecentered and bodycentered lattices, respectively. The lattice types of NaCl and CsCl, respectively, are a) F and I b) F and P d) P and I c) I and P

Which of the following statement(s) is (are) correct (a) The coordination number of each type of ion in CsCl crystal is 8. (b) A metal that crystallizes in bee structure has a coordination number of 12. (c) A unit cell of an ionic crystal shares some of its ions with other unit cells. (d) The length of the unit cell in NaCl is 552 pm. (95 pm r