Chemistry Questions and Answers April 30, 2020

The height limit used for the design of stairshaft pressurization systems is more restrictive for Select one a. Winter conditions b. Summer conditions c. No difference between winter and summer conditions

Complete the following table. Table D. Calculated vs Measured pHs for Na,co3 Titration mL of 0.20 M HCI added Calculated pH Measured pH (from prelab) (from titration curve) 49 11.10 0.00 11.66 4.0 5.00 10.329 4.0 10.10 8.34 40 8.23 10.00 40 6.36 15.00 6.352 5.30 494.00 20.00 2.021 40 2.79 22.00 InLab Question 7a. What are the experimental pk

1. Where are carbon atoms forced to go in GaAs with less Ga(CH3)3 and more AsH3? 2. Can you guess why there is a singularity in the figure where the net carrier concentration goes to zero? You can assume that the total carbon concentration in GaAs is constant.

Carrier Concentration (cm) (e) The following figure shows how the ratio of AsH3 to Ga(CH3)3 partial pressures in MOCVD affects the conduction type (n or p) and net carrier concentration of the GaAs film (S. Ito, T. Shinohara, and Y. Seki, Journal of the Electrochemical Society, vol. 120, p. 1419 (1973)). With more Ga(CH3)3 and less AsH3, the GaAs

If you have 168 grams of C 6 H 12 O 6 (glucose), how many moles of glucose do you have? How many molecules of glucose do you have? How many hydrogen atoms do you have?

Manufacturing planning and control (mpc) includes which of the following activities i material management ii product marketing iii coordinating suppliers a i only b ii only c iii only d i and iii

For fuel-lean combustion of a fuel C x H y O z with air, derive an expression for the emission index of water (EI H2O ), making our usual first approximations. Your result should contain (at most) the numbers of atoms of carbon, hydrogen, and oxygen in the fuel molecule, element atomic weights, and species molecular weights.

The condensation reaction of acetone in aqueous solution occurs when a base B reacts reversibly with acetone to form a carbanion C3H5O. The carbanion then reacts with a molecule of acetone to give the product. A simplified version of the reaction mechanism is k A k, product where HA stands for acetone and A its carbanion. a) Using the

An approximately 0.1 M NAOH solution is made by adding 4.0 g of solid NaOH to 1000 ml of water. The precise concentration of the solution is determined by titrating the NaOH against portions of a weak acid, potassium acid phthalate (KHP) obtained from the National Bureau of Standards and certified as being 99.99 pure. The KHP samples are weighed

If two moles of CH 3 Br reacts with three moles of I - how much heat energy is involved in the reaction? a) 19 kJ b) 76 kJ c) 114 kJ d) 38 kJ

Make a detailed and creative infographic of Penicillin

Which of them typically occur in an electron impact (EI) ion source? 1. Molecular ion formation (ionization) 2. Fragmentation 3. Protonation 4. sN2

1. The dissolved oxygen concentration in a water sample with 4.3 mg/L chlorinity was measured at 0.83 atm and 22. The DO obtained was 5.34 mg/L. Using the formulas from the DO saturation standards Table 4500, find the maximum oxygen saturation and compare your values to the ones reported. Calculate the percentage error.

A 0.0647mol sample of a nutrient substance, with a formula weight of 114 g/mol, is burned in a bomb calorimeter containing 7.22 10 2 g H 2 O. Given that the fuel value is 3.69 10 1 in nutritional Cal when the temperature of the water is increased by 3.77C, calculate the fuel value in kJ.

Is the following molecule chiral Yes No

How much work, w, must be done on a system to decrease its volume from 12.0 L to 3.0 L by exerting a constant pressure of 3.0 atm w kJ

(b) Into how many peaks will the signal for each of the Indicated protons be split in HNMA Br 2

1a. A manual creatinine lab was performed in an MLS student lab. The Absorbance of the 5.0 mg/dL creatinine standard was 0.512. The QC 2s sample absorbance was 0.492. What is the concentration in mg/dL of QC 2? 1b. If the acceptable range of the QC2 material in question 5 has a mean of 4.4mg/dL and a standard deviation of 0.1 mg/dL is the run of

The vapor pressure of the benzene at different temperatures is given in the table on the side. Match this Clapeyron equation (linear model). Clapeyron equation log P A BT Here T is absolute temperature (K), P pressure (Pa), A and B are parameters of equation. a. (15 points) Calculate the parameters of equation and coefficient of determination

Question 3 What is wrong with the following orbital spin diagram tt 1s O One arrow should be in the 1s and one arrow should be in the 1p. One arrow should be pointing up and one arrow should be pointing down. O The 1s has two orbitals so one arrow should be in the first 1s orbital and the other arrow should be in the second 1s orbital. O Both

Which of the following represents the most stable conformation for propane? Which of the following compounds have N atom with delocalized electrons? In its launching year, the drug (structure below) was used by over three million satisfied customers. Determine the number of chiral carbons in this drug.

HH fr54erre H.H HCH H de76545

The volume of solution of calcium chloride CaCl2 and water at temperature 18C and atmospheric pressure is determined the empirical equation 3 V 1000 10.15n 3.52n2 1.62n This equation is satisfied for a mole number of calcium chloride n ranging from 0.1 to 1.0 V is the volume of the solution in cm. Calculate the partial molar volumes of calcium

Consider the most stable conformation of the 2,3dibromopentane molecule shown below. Which of the following statements are true about this structure Br Br

Write the IUPAC name of the 1 point following molecule Lowercase letters only and DO NOT put space in between. DO NOT include stereochemistry. Your answer ,Write the IUPAC name of the 1 point following molecule Lowercase letters only and DO NOT put space in between. Gray balls represent C, white balls represent H. Do not include stereochemistry.

Write the IUPAC name of the 1 point following molecule Lowercase letters only and DO NOT put space in between. Included CISTRANS isomerism in the name. I Your answer ,Optical isomerism occurs due to difference in the rotation of plane 1 point polarized light that is, due to optical rotation by asymmetric molecules. Which of the choices below is

Select the meso compound in the 1 point choices below OH H rggrr554 CH,OH CH,OH ffffhfghgt ,H. OH OH dder4 Et Et Et Et ddrhh6 ,Identify EZ configuration of the 1 point following molecule 1. 2. 3. 4. Br O 1. Z, 2. Z, 3. E, 4. E 1. Z, 2. E, 3. Z, 4. E O 1. Z, 2. Z, 3. E, 4. Z O 1. E, 2. Z, 3. E, 4. Z ,The absolute configuration of the 1 point

Write the IUPAC name of the 1 point following molecule Lowercase letters only and DO NOT put space in between. If there is a complex substituent, name it using abbreviatedspecial names. Include EZ configuration in the name. Your answer ,Which of the following electron 1 point density map correctly illustrates an alkane u8p70igker4 O 76599i24

The ratio of sigma to pi bonds in the 1 point structure below is O 7 6. 3 ,In which of the following compounds 1 point is delocalizable bonding impossible nmh765lgflv dfdvv99644 ,O dfbgj89965tgf vcfrerk4353 ,Where are the two lone pairs of 1 point electrons of the oxygen atom in the molecule given below located in two s orbitals in two sp3

If 25 mMoles of Lidocaine (MW 234.33, pKa7.87) is added in a two phase system containing 150 ml of water buffered at pH 7.4 and 150 ml of Octanol. If the partition coefficient of the unionized species (Kd) is 7.77, calculate the overall partition coefficient. The apparant partition cofeeicient at pH 7.41)

The molecule shown below is a 1 point potential drug for osteoporosis. Which of the following bonds in the choices is the strongest 16 15 10 HN12 13 14 N C10011 C2C3 C3C4 C14N15 C8C9 ,Among the four structures in the 1 point choices, one is not a valid resonance form. Identify the wrong structure. CH, CH2 CH3 dfhj76 CH, 3D CH3 deefr7 ,CH,N0

Which statement is false 1 point Orbitals are regions of space where electrons are found, Orbitals may contain up to two electrons. Orbitals of equivalent energy are half filled before adding two electrons to any one of them. Orbitals are filled in order of decreasing energy. Determine the estimated CC 1 point bond angles in degrees at positions I

21. Determine the mass in grams of each of the following (a) 0.600 mol of oxygen atoms (b) 0.600 mol of oxygen molecules, O2 (c) 0.600 mol of ozone molecules, O3

3. Calculate the molecular or formula mass of each of the following (a) P4 (b) H2O (c) Ca(NO3)2 (d) CH3CO2H (acetic acid) (e) C12H22011 (sucrose, cane sugar)

How many grams are in 8.13 x 1023 molecules of CH4

How many grams are there in 1.60 x 1024 molecules nitrogen dioxide, NO2

QUESTION 12 How many grams are there in 2.30 x 10 1024 atoms of silver

Determine the mass of zirconium a, silicon b, and oxygen c found in 0.3384 mol of zircon, ZrSiO, a semiprecious stone. Your answer must have the correct number of significant figures. 4

How many grams does 5.60 x 1022 molecules of SiO2 weigh

How many grams does 0.500 moles of copper (I) bromide weigh

21. Determine the mass in grams of each of the following (a) 0.600 mol of oxygen atoms (b) 0.600 mol of oxygen molecules, O2 (c) 0.600 mol of ozone molecules, O3

Determine the mass of zirconium [a], silicon [b], and oxygen [c] found in 0.3384 mol of zircon, ZrSiO 4

131. The spacing between the lines in the microwave spectrum of HCl is 6.350 x 10 Hz. Calculate the bond length of H CI.

The reaction A 3B C has K. (5.15x1016) and is started with (A) 15 M and (B 9 M. What is the equilibrium (B

1) What is the reaction mechanism? (Esterification) Please Explain also. Starting Materials: 2-Phenylacetic acid and 3-Methy-1-Butanol Solvent: Diethyl ether Reagent: Sulfuric Acid Product: 3-Methylbutyl phenylacetate

1. Water containing chlorate, CIO, is to be treated by ion exchange using a strong base resin (Type II, CH form). The wetresin total ion exchange capacity (q) is equal to 1.25 eqL. The water contains 5 mgL of chlorate, and 10 mgL chloride. Assume all other anions are negligible and use selectivity coefficients to calculate your answers. a)

3. Which of the following measurements has the lowest temperature A) T 36C B) T 54F C) T310 K D) All of these temperatures are equal 4. Which of the following statements is not true about table salt (NaCl) A) NaCl is a compound B) NaCl is held together by covalent bonds C) NaCl contains a metal and a nonmetal D) NaCl contains the same number of

Please provide a mechanism for the following OH COH HPO SbFs SO CIF (solvent) 78 C

If the following two reactions were coupled, what would be the overall AG Glucose Pi Glucose6Phosphate AG 13.8 kJmol ATP H20 ADP Pi AG 30.5 kJmol 44.3 kJmol 16.7 kJmol 16.7 kJmol 44.3 kJmol

(20) In an ethanolwater solution at 20 C, the vapor pressure of ethanol at 40 wt ethanol is 20.7 torr and that of the water is 14.7 tor. The pure vapor pressure of ethanol is 43.6 torr and of water 17.5 torr at 20 C. Calculate the activity and activity coefficient of ethanol in this solution.

Conjugate addition reactions that use methyl vinyl ketone (MVK) can have sidereactions due to polymerization. For each of reactions below, decide if polymerization would be a serious problem, and justify your answer with diagrams accompanied by brief comments. Solvents are written in blue. polymerization problem (circle) brief explanation NEta.

Two of the most important cathodic processes in aqueous corrosion cells are the reduction of dissolved oxygen and the reduction of hydrogen ions. On an iron surface the exchange current density, io for proton reduction is about l0-6 A/cm2 whereas that for the oxygen reaction is about 10-14A/cm2 . How might you account for this large difference in

What is the product of the following reaction below Q82 What is the product of the reaction below e A B OH OH E H,O HO HO HO Select an answer and submit. For keyboard navigation, use the updown arrow kays to select an answer. a by P. D. B. C.

1. Given the following table, please calculate svalues for the effects of p methoxy and pnitro substituents on the acidity of benzoic acids. Ka of Substituted Benzoic Aci 6.46 x 105 3.50 x 105 Substituent X H X OCH3 X NO2 3.90 x 104 a. What does the sign of the svalue of a substituent mean for its effect on the stability of the transition state

Consider the following reaction 2 P(e) 3 H2) 2 PH3(2) (assume P) is white P) a) Use tabulated data in the text to calculate K, for this reaction at 298 K. b) Use tabulated data in the text to determine K, at 550 K assuming AHR is independent of temperature. c) Assuming the reaction is begun with n, moles of H2, excess Pe), and no PH3, derive a

Question 3 Consider the mordant dyes and alizarin red S results, specifically focusing on the use of copper (II) in solution. The dye was ( Select v to water, Select v to cyclohexane, Select to diethyl ether and Select) to the 5 H2O2 solution. Options are Completely Resistant Not esistant Partially Resistant Copper Mordant Cu2 cOPPEROn SULFATE

Different types of defects in ionic structures may interact with each other strongly. These interactions usually result in drastic changes in the properties of the material. One such interaction is the so-called space-charge region between the point defects and surfaces/interfaces. What is a space-charge region? Use MgO as an example and tell us

When methane is burned with oxygen, carbon dioxide and water are produced. If you produce 9 grams of water and 11 grams of carbon dioxide from 16 grams of oxygen, how many grams of methane were needed for the reaction? A) 4 B) 20 C) 31 D) 40

What is the hydronium ion concentration in an aqueous hydrochloric acid solution with a pH of 3.530 ? [H 3 O + ] = M

What is the pH of an aqueous solution of 3.6910 -3 M hydrobromic acid ? pH =

What is the pH of an aqueous solution of 4.8110 -3 M barium hydroxide ? pH =

The pH of an aqueous solution of 0.325 M phenol (a weak acid) , C 6 H 5 OH, is .

In the laboratory, a general chemistry student measured the pH of a 0.325 M aqueous solution of hypochlorous acid to be 3.988 . Use the information she obtained to determine the K a for this acid. K a (experiment) =

The hydronium ion concentration of an aqueous solution of 0.325 M aniline (a weak base with the formula C 6 H 5 NH 2 ) is ... [H 3 O + ] = M.

The pH of an aqueous solution of 0.325 M diethylamine (a weak base with the formula (C 2 H 5 ) 2 NH) is .

The pH of an aqueous solution of 0.128 M ammonium bromide , NH 4 Br (aq), is . This solution is _________ acidic basic neutral

The pH of an aqueous solution of 0.1750 M hydrosulfuric acid , H 2 S (aq), is .

A buffer solution is 0.396 M in HClO and 0.271 M in NaClO . If K a for HClO is 3.510 -8 , what is the pH of this buffer solution?

A buffer solution is 0.356 M in H 2 SO 3 and 0.217 M in NAHSO 3 . If Ka1 for H 2 SO 3 is 1.7x10-2 , what is the pH of this buffer solution?

A buffer solution made from HCIO and NaCIO has a pH of 7.21. If pK, for HC1O is CIO 7.46, what is the in the buffer HCIO CIO HCIO

The pK, value for H2 CO3 is 6.38. What mole ratio of NaHCO3 to H2CO3 is needed to prepare a buffer with a pH of 6.03 HCO3 H,CO3 ment

A 1.00 liter solution contains 0.38 moles acetic acid and 0.29 moles potassium acetate . If 0.15 moles of perchloric acid are added to this system, indicate whether the following statements are true or false. (Assume that the volume does not change upon the addition of perchloric acid .) _______ True False A. The number of moles of CH 3 COOH will

A 1.00 liter solution contains 0.30 M ammonia and 0.39 M ammonium bromide . If 0.098 moles of barium hydroxide are added to this system, indicate whether the following statements are true or false. (Assume that the volume does not change upon the addition of barium hydroxide .) _______ True False A. The number of moles of NH 3 will remain the same

A buffer solution contains 0.464 M Na HCO 3 and 0.276 M Na 2 CO 3 . Determine the pH change when 0.064 mol HI is added to 1.00 L of the buffer. pH change =

Determine the pH change when 0.047 mol HBr is added to 1.00 L of a buffer solution that is 0.356 M in HNO 2 and 0.217 M in NO 2 - . pH after addition pH before addition = pH change =

A solution contains 0.210 M potassium hypochlorite and 0.265 M hypochlorous acid . The pH of this solution is .

A solution contains 8.7410 -2 M potassium nitrite and 0.176 M nitrous acid . The pH of this solution is .

The compound dimethylamine is a weak base like ammonia. A solution contains 0.418 M (CH 3 ) 2 NH 2 + and 0.134 M dimethylamine , (CH 3 ) 2 NH . The pH of this solution is .

The compound ethylamine is a weak base like ammonia. A solution contains 0.225 M C 2 H 5 NH 3 + and 0.205 M ethylamine , C 2 H 5 NH 2 . The pH of this solution is .

How many grams of solid ammonium bromide should be added to 1.00 L of a 0.120 M ammonia solution to prepare a buffer with a pH of 8.710 ? grams ammonium bromide = g.

A 19.5 mL sample of a 0.378 M aqueous nitrous acid solution is titrated with a 0.332 M aqueous sodium hydroxide solution. What is the pH at the start of the titration, before any sodium hydroxide has been added? pH =

What is the pH at the equivalence point in the titration of a 17.2 mL sample of a 0.348 M aqueous hydrocyanic acid solution with a 0.314 M aqueous sodium hydroxide solution? pH =

A 26.3 mL sample of 0.271 M ammonia , NH 3 , is titrated with 0.296 M hydroiodic acid . The pH before the addition of any hydroiodic acid is.

A 21.7 mL sample of 0.217 M ammonia , NH 3 , is titrated with 0.256 M hydrobromic acid . At the equivalence point, the pH is. Use the Tables link in the References for any equilibrium constants that are required.