How many moles of N2(g) are in a 960.0 mL container at 650 mmHg and 55.0∘C ? 30.5 mol 0.000301 mol 23.2 mol 0.0305 mol 0.182 mol
A mixture of 1.0 moles of H2 and 1.0 moles of I2 was placed in a 10.0 L flask at 700 K. The equilibrium constant for the reaction is 57.0. Calculate the concentration of HI at equilibrium. H2(g) + I2(g) "yields" 2HI(g) 0.079 M 0.021 M 1.0 M 0.16 M
A 662 mL sample of gas contains 0.0496 moles and kept at 341 K. What is the pressure of the gas in torr? R = 0.08206 L atm mol K Do not include units with your answer
Part A How many moles of an ideal gas exert a gauge pressure of 0.846 atm in a volume of 5.13 L at a temperature of 22.2∘C. Express your answer in moles.
Balance the following redox reaction in acidic solution. ClO3− + I2 → Cl− + IO3− How many moles of of Cl− form when 0.958 moles of I2 completely react with ClO3−? Record your answer to three sig figs.
For a certain substance the concentration (in moles per liter, mol/L) is found by using the formula C = −2500 ln(I I0) where I0 is the intensity of the incident light and I is the intensity of light that emerges. Find the concentration of the substance if the intensity I is 70% of I0. moles/liter (correct to two decimal places)
One mole of N2 and 3 moles of H2 are placed in a flask at 397∘C. Calculate the total pressure of the system at equilibrium if the mole fraction of NH3 is found to be 0.236. The KP for the reaction is 4.31×10−4. Be sure your answer has the correct number of significant digits.
Which of the following has the GREATEST number of molecules? 1.25 moles CH4 They all have the same number of molecules. 1.25 moles P2O5 1.25 moles Cl2 1.25 moles H2O
The following reaction is first order with a rate constant of 0.595 1/hr: X3Z4(g) ⟶ 3X(g) + 4Z(g) If 3.00 moles of X3Z4 are reacted for 187 minutes, how much (in moles) of Z can be produced? Enter a number to 2 decimal places in moles of Z.
How many moles of hydrogen are in 7.0 moles of the antibiotic amoxicillin, C16H19N3O5S ? (Molar mass of amoxicillin: 365.40 g/mol ) 2.71 mol H 133 mol H 6.022×1023 mol H 2600 mol H 19 mol H
Determine the theoretical yield of H2S (in moles) if 4.0 mol Al2S3 and 4.0 mol H2O are reacted according to the following balanced reaction. (The molar mass of Al2S3 = 150.17 g/mol) Al2S3(s) + 6H2O(l) → 2Al(OH)3(s) + 3H2S(g) 6.0 mol H2S 2.0 mol H2S 12 mol H2S 4.0 mol H2S 18 mol H2S
Entropy of steam. Calculate the entropy change of steam between states P1 = 36 bar, T1 = 250∘C and P2 = 22 bar, T2 = 400∘C by direct application of the definition of entropy. Compare with steam table values. Hint. Devise a path of constant pressure followed by a path of constant volume that connects the two states. Use tabulated values of U and H to calculate the required heat capacities.
Entropy of ethanol. Ethanol (C2H5OH) vapor at 0.5 bar and 78∘C is compressed isothermally to 2 bar in a reversible process in a closed system. a. Draw a qualitative PV graph and show the path of the process. Mark all the relevant pressures and isotherms b. Calculate the enthalpy change of the ethanol. c. Calculate the entropy change of the ethanol. d. What is the amount of heat exchanged between the ethanol and the surroundings during the compression? Assume the ethanol vapor is an ideal gas with CP = 45 J/mol/K. The saturation pressure of ethanol at 78∘C is 1 bar.
Work, entropy and steam. Steam is compressed by a reversible isothermal process from 15 bar, 250∘C, to a final state that consists of a vapor-liquid mixture with a quality of 32%. a. Calculate the amount of work. b. Calculate the amount of heat that is required to maintain isothermal conditions. Is this heat added or removed from the system?
Reversible adiabatic compression of steam. Steam at 1 bar, 150∘C is compressed in a closed system by a reversible adiabatic process to a final pressure of 20 bar. Determine the final temperature and the amount of work.
What is the symbol for the atom that has 9 protons, 10 neutrons and 9 electrons? Hint: What information can you use to determine the identity of the atom?
If a nucleus were the size of a golf ball (diameter = 4.3 cm ) what is the diameter of the "atom" with a nucleus this size? (Give your answer in meters. ) Hint: What is the ratio of the atom diameter to the diameter of the nucleus? (See Figure F01-1-1)
The symbol for one of the stable isotopes of sulfur can be written: 34 S. How many protons, neutrons and electrons are in this isotope? Hint: What does the superscript 34 tell you about the atom?
Magnesium has three naturally occuring isotopes. The masses and % abundances of the isotopes are given in the table below. What is the average atomic mass of Mg ? Hint: Use E01-1-2: don't forget to convert the % abundances to fractional abundances (decimals).
A student weighs 20 M&Ms and finds that the average weight of a single M&M is 0.8695 g. How many M&Ms are in a 1 lb (453.6 g) bag of M&Ms? Hint: Assume that all of the M&Ms have the average mass of a single M&M.
Four representations of the ethanol molecule are given below. Match each of these representations with its name. A. Structural formula B. Space filling model C. Ball and stick model D. Molecular formula
A. What is the change in internal energy for each of the following situations? I. q = 7.9 J out of the system and w = 3.6 J done on the system II. q = 1.5 J into the system and w = 7.5 J done on the system B. Assuming both of these systems had the same internal energy initially, which of the two is lower in energy (more stable) after these changes?
Referring to the picture below, which of these statements are true? i. The distance traveled from A to B along the straight line path is a state function. ii. The distance traveled on the curved path from A to B is a state function. iii. The change in elevation from point A to B (Δ) is a state function.
Assuming the distance d is the same for all of these, rank them in order of increasing electrostatic potential energy.
If the following processes take place at constant pressure, which will be exothermic and which will be endothermic? I. Gasoline burns. II. Two solids at room temperature are mixed and the temperature of the mixture decreases to 15∘C.
What is the frequency of the wave shown below assuming it is light (electromagnetic radiation)?
Which of the following processes has a positive value for ΔE and which are endothermic? i. A system absorbs 50 kJ of heat from the surroundings and does 30 kJ of work on the surroundings. ii. A system releases 25 kJ of heat into the surroundings and 45 kJ of work is done on the system. iii. q = 12.5 kJ, w = – 3500 J
A particular microwave photon has a wavelength of 0.01 m, a photon of green visible light has a wavelength of 520 nm and a photon of gamma radiation has a wavelength of 8 pm. Rank these forms of electromagnetic radiation in order of increasing energy and frequency. Frequency (v) : Energy (E) : What general trend do we see?
I. What is the wavelength of one ultraviolet (uv) photon if the frequency is 1.50×1015 s−1 ? II. What is the energy of one uv photon of this frequency? III. What is the energy of one mole of uv photons of the same wavelength?
An Argon laser gives off pulses of green light (wavelength = 514 nm). If a single pulse from the laser has a total energy of 10.0 mJ how many photons are in the pulse?
Green light of wavelength 516 nm is absorbed by an atomic gas. I. What is the energy difference between the two quantum states involved in the transition? II. If the gas absorbed a mole of photons, what is the total energy that would be absorbed?
The energy level diagram for a hypothetical one-electron quantum system is shown below. Assuming these are the only possible energy levels, and that they are equally spaced, how many lines would there be in the emission line spectrum?
I. Which of the following electron transitions in a hydrogen atom will emit a photon? II. Which of the following electron transitions in a hydrogen atom will be caused by the absorption of a photon? (How do you know? ) III. Which of the electron transitions below will result in emission of light with the longest wavelength? a. n = 1 to n = 3 b. n = 4 to n = 3 c. n = 3 to n = 2 d. n = 3 to n = 1 e. n = 2 to n = 3
I. How many possible subshells have n = 3 ? II. How many orbitals have n = 3 and mℓ = −1 ? III. Identify the subshell for each set of quantum numbers below (if the quantum numbers identify a possible state). Which are not permissible sets of quantum numbers? n = 3, ℓ = 0, mℓ = 0 n = 3, ℓ = 2, mℓ = 2 n = 3, ℓ = 1, mℓ = −1 n = 3, ℓ = 3, mℓ = 0 n = 3, ℓ = 2, mℓ = −3
What are the possible subshells when the principle quantum number is n = 4 ? Rank these subshells in order of increasing energy for the hydrogen atom a multi electron atom In the multi electron atom, which of the n = 4 orbitals ( 4 s, 4 p, 4 d, or 4 f ) will have an electron that experiences the greatest effective nuclear charge? Which will have the smallest Zeff?
Which of the following have the correct sequence of orbitals in a multi electron atom from lowest to highest energy? If the orbitals are NOT in order of increasing energy, put them in the correct order. I. 2p < 3s < 2s II. 3p < 4s < 3d III. 3p < 3d < 4s IV. p < 2s < 1s V. 3s < 4s < 3p
In which one of these orbitals does an electron experience the greatest effective nuclear charge? Which will experience the smallest Zeff ? 1s 2s 2p 3s 3p
I. Rewrite the electron configurations for the atoms below using core electron notation. II. Determine the number of valence electrons for each atom. B 1s22s22p1 Ca 1s22s22p63s23p64s2 Cl 1s22s22p63s23p5
The following electron configurations correspond to neutral atoms in excited states. What is the element and what is the ground state electron configuration for each atom? 1s22s22p63s23p63d5 [Kr]5s24d105p46s1
I. What is the ground state electron configuration of Fe ? II. How many valence electrons does iron have? III. How many unpaired electrons are in the ground state of Fe ?
Write out the electron configurations of the following atoms using an inert gas core. For each atom, give the orbital that will have the VALENCE electron that will experience the smallest effective nuclear charge? Which will experience the greatest Zeff ? S Cu
Which electron configuration violates Hund's rule? Which violates the Pauli exclusion principle? Which violates both?
Use the Interactive Periodic Table to answer the following questions about atomic radius. Start by selecting the Periodic Table link on the upper right side of the page beneath the SF6 molecule. Using the pull down menu at the bottom of the table, select atomic radius. I. What is the atomic radius of selenium (atomic number 34 )? II. Plot the radius of the group 1 elements. What trend do you see in radius? III. What trend do you think you will you see if you plot any other group? (Check your prediction.)
Use the Interactive Periodic Table to answer the following questions about ionization energy. I. What is the first ionization energy (IE1) of sulfur (atomic number 16)? II. Write the expressions for the successive ionization energies of S(IE1 to IE7) ? III. Plot the successive ionization energies of S(IE1 to IE7). IV. What trend is seen in this plot? How do you explain the change in slope associated with the IE7 ?
Use the Interactive Periodic Table to answer the following questions about ionization energy. Start by selecting the Periodic Table link on the upper right side of the page beneath the SF6 molecule. Using the pull down menu at the bottom of the table, select ionization energy. I. Plot the first ionization energies (IE1) of the group 1 elements. What is the trend in IE1 ? II. What trend do you think you will you see if you plot any other group? (Check your prediction.) III. Compare the trend in IE1 to the trend in atomic radii. Is there a connection?