Questions and Answers of General Chemistry

The n quantum number of an atomic orbital is 5. What are the possible values of l? What are the possible values of ml if the l quantum number is 4?
The energy of a photon is 2.70 × 10-19 J. What is the wavelength of the corresponding light? What is the color of this light?
The energy of a photon is 3.05 × 10-19 J. What is the wavelength of the corresponding light? What is the color of this light?
Calculate the wavelength of the Balmer line of the hydrogen spectrum in which the initial n quantum number is 3 and the final n quantum number is 2.
What is the wavelength of the transition from n = 4 to n = 2 for Li2+? In what region of the spectrum does this emission occur? Li2+ is a hydrogen-like ion. Such an ion has a nucleus of charge +Ze
List the possible subshells for the n = 8 shell.
A particular microwave oven delivers 750 watts. (A watt is a unit of power, which is the joules of energy delivered, or used, per second.) If the oven uses microwave radiation of wavelength 12.6 cm,
The photoelectric work function of potassium is 2.29 eV. A photon of energy greater than this ejects the electron with the excess as kinetic energy. Suppose light of wavelength 455 nm ejects an
A ruby laser puts out a pulse of red light at a wavelength of 694 nm. (The ruby laser is described in the essay on p. 226.) If a pulse delivers 1.05 × 105 watts of power for 280 цs, how many
The retina of the eye contains two types of light sensitive cells: rods (responsible for night vision) and cones (responsible for color vision). Rod cells are about a hundred times more sensitive to
Ozone in the stratosphere absorbs ultraviolet light of wavelengths shorter than 320 nm, thus filtering out the most energetic radiation from sunlight. During this absorption, an ozone molecule
Hydrogen-like ions are atomic ions consisting of just one electron about a nucleus. The energy levels of such an ion are given by a formula similar to that of the hydrogen atom except that the
An electron is accelerated through a potential difference of 15.6 kilovolts (giving the electron a kinetic energy of 15.6 keV). What is the associated wavelength of the electron in angstroms?
In X-ray fluorescence spectroscopy, a material can be analyzed for its constituent elements by radiating the material with short-wavelength X rays, which induce the atoms to emit longer-wavelength X
In a hypothetical universe, the quantum numbers for an atomic orbital follow these rules:n = any positive integer value from 2 to ∝l = any positive integer value from 2 to n + 1ml = any integer
The table below is partially completed for subshells A and B, where subshell B is the next subshell higher in energy compared to subshell A. For example, if subshell A is the 4s subshell, then
The table below is partially completed for subshells A and B, where subshell B is the next subshell higher in energy compared to subshell A. For example, if subshell A is the 4s subshell, then
What is the maximum number of electrons that can occupy a f subshell (l = 3)?
List the orbitals in order of increasing orbital energy up to and including 3p orbitals.
What atom has the smallest radius among the chalcogens.
The ions K+ and Ca2+ occur in chemical compounds, but the ions K2+ and Ca3+ do not. Explain.
Describe the major trends in metallic character observed in the periodic table of the elements.
What would you predict for the atomic number of the chalcogen in Period 7?
Give the names and formulas of two oxides of carbon.
Phosphorus has _________ unpaired electrons.a. 1 b. 2 c. 3 d. 4 e. 5
Consider the following orderings.I. Al < Si < P < SII. Be < Mg < Ca < SrIII. I < Br < Cl < FWhich of these give(s) a correct trend in atomic size?a. I onlyb. II onlyc. III
Two elements in Period 4 are adjacent to one another in the periodic table. The ground-state atom of one element has only s electrons in its valence shell; the other has at least one d electron in an
Give the electron configuration of the ground state of tellurium, using the building-up principle.
Use the building-up principle to obtain the groundstate configuration of arsenic.
Barium is a Group 2A element in Period 6. Deduce the valence-shell configuration of barium.
Bismuth is a Group 5A element in Period 6. Write the valence-shell configuration of bismuth.
Tungsten is a Group 6B element in Period 6. What would you expect for the valence-shell configuration of tungsten?
Manganese is a Group 7B element in Period 4. What would you expect for the configuration of outer electrons of manganese?
Using periodic trends, arrange the following elements by increasing ionization energy: Ar, Na, Cl, Al.
Write the simplest formulas expected for two oxides of selenium.
Write the complete ground-state electron configuration of the strontium atom, Sr, using the building-up principle.
Write the complete ground-state electron configuration of the tellurium atom, Te, using the building-up principle.
Obtain the valence-shell configuration of the polonium atom, Po, using the position of this atom in the periodic table.
Obtain the valence-shell configuration of the lead atom, Pb, using the position of this atom in the periodic table.
Write the orbital diagram for the ground state of the selenium atom. Give all orbitals.
For eka-lead, predict the electron configuration, whether the element is a metal or nonmetal, and the formula of an oxide.
From Figure 8.18, predict the first ionization energy of francium (Z = 87). 2500 He 2000 * 1500 Kr Br As Rn E 1000 Bi S00 Li Ca Sr Na In Ba K Rb Cs 10 18 36 54 86 Atomic number, Z -Ne 吕 550 1008 At
From Figure 8.18, predict the first ionization energy of ununseptium (Z = 117). 2500 He 2000 * 1500 Kr Br As Rn E 1000 Bi S00 Li Ca Sr Na In Ba K Rb Cs 10 18 36 54 86 Atomic number, Z -Ne 吕 550
What property of an atom does nuclear magnetic resonance depend on? What frequency range of the electromagnetic spectrum does NMR use?
Explain the origin of the “chemical shift” seen for a proton in a molecule.
Researchers have shown that it is possible to levitate diamagnetic materials. What animal did they use in their experiments to show this?
A metallic element, M, reacts vigorously with water to form a solution of MOH. If M is in Period 5, what is the ground-state electron configuration of the atom?
A nonmetallic element, R, burns brightly in air to give the oxide R4O10. If R is in Period 3, what is the ground state valence-shell configuration of the atom?
The ground-state electron configuration of an atom is 1s22s22p63s23p4. What is the valence-shell configuration of the atom in the same group, but in Period 5?
An atom of an element has the following ground state configuration: [Kr]4d105s25pb. If the element is in Group 6A, what is the symbol of the element? What is b?
A moderately reactive metallic element (whose melting point is 850°C) burns in a container of a greenish gas (also an element) to produce a white solid. The white solid dissolves in water to form a
A metallic element reacts vigorously with water, evolving hydrogen gas. An excited atom of this element has its outer electron in the 3p orbital. When this electron drops to its ground state in the
All elements up to atomic number 118 have been discovered. What electron configuration would you expect for the yet-to-be discovered element 120? Explain your answer.
The densities (in g/cm3) of some elements in Period 5 that span indium, In, are as follows: Ag, 10.49; Cd, 8.65; Sn, 7.31; and Sb, 6.68. Plot the density of each element against its atomic number.
List three elements in order of increasing ionization energy. Two of the elements should be halogens (but not F), and the other should be Se.
The energy of dissociation of the Cl2 molecule is 240 kJ/mol. Using the appropriate data from this chapter, calculate the energy obtained (or released) in adding electrons to the Cl2 molecule to
The electron affinity of the lutetium atom (element 71) was measured using the technique of photoelectron spectroscopy with an infrared laser (the essay on p. 310 describes this instrumental method,
A 2.17-g sample of barium reacted completely with water. What is the equation for the reaction? How many milliliters of dry H2 evolved at 21°C and 748 mmHg?
A 12.1-g sample of Na2SO3 is mixed with a 14.6-g sample of MgSO4. What is the total mass of oxygen present in the mixture?
Calcium carbide, CaC2, used to produce acetylene, C2H2, is prepared by heating calcium oxide, CaO, and carbon, C, to high temperature.CaO(s) + 3C(s) → CaC2(s) + CO(g)If a mixture contains 8.49 kg
Methanol, CH3OH, is prepared industrially from the gas-phase catalytic balanced reaction that has been depicted here using molecular models.In a laboratory test, a reaction vessel was filled with
Nickel(II) chloride reacts with sodium phosphate to precipitate nickel(II) phosphate.3NiCl2(aq) + 2Na3PO4(aq) → Ni3(PO4)2(s) + 6NaCl(aq)How many moles of nickel(II) chloride are needed to produce
From the following written description, write the balanced chemical equation for the reaction including state symbols. A diatomic gaseous molecule that contains 17 protons per atom is reacted with a
Write the balanced chemical equation for the reaction of an aqueous oxacid that contains the phosphate anion with solid magnesium hydroxide. The reaction produces liquid dihydrogen monoxide and a
Starting from ground level with the graduation of Atomic University’s Class of 2018, strings of Au atoms (diameter = 288 pm) are to be bonded to one another in a vertical fashion until the top of
Write the formulas and names for all the ionic compounds that can form by combinations of the following ions: Mg2+, Cr3+, the carbonate anion, and the nitride anion.
Name the following compounds:SO3HNO2Mg3N3HI(aq)Cu3(PO4)2CuSO4·5H2O
The IO3– anion is called iodate. There are three related ions: IO–, IO2–, and IO4–. Using what you have learned about similar groups of anions, write the name for each of the following
Write out in words the following chemical equations:a. PbCl2(aq) + Na2S(aq) h PbS(s) + 2NaCl(aq)b. H2O(l) + SO3(g) → H2SO4(aq)c. C(s) + O2(g) → CO2(g)d. H2(g) + I2(g) → 2HI(g)
An 18-mL sample of water contains 6.0 × 1023 water molecules. Assuming that this sample consists only of the Hydrogen-1 and Oxygen-16 isotopes, calculate the number of neutrons, protons, and
Name the following compounds:a. HCl(g)b. HBr(aq)c. HF(g)d. HNO3(aq)
During nuclear decay a 238U atom can break apart into a helium-4 atom and one other atom. Assuming that no subatomic particles are destroyed during this decay process, what is the other element
a. Complete the following table for an isotopically labeled atom or ion:b. Complete the following table for an isotopically labeled atom or ion: Metal, Metalloid, or Nonmetal? Name or Symbol (example
A mixture is made up of 4 molecules of CH3CH2 CH2OH and 5 formula units of Pb3(PO4)4∙6H2O. Why are the terms “molecules” and “formula units” used for the two substances?a. Molecules
A power plant is driven by the combustion of a complex fossil fuel having the formula C11H7S. Assume the air supply has a N2/O2 molecular ratio of 3.76:1.00 and the N2 remains unreacted. In
The element europium exists in nature as two isotopes: 151Eu has a mass of 150.9196 amu, and 153Eu has a mass of 152.9209 amu. The average atomic mass of europium is 151.96 amu.a. Calculate the
A Complete and balance the following reactions:a. The complete combustion of C4H10O with O2:C5H10O __________ → __________b. Pb(s) + __________ → __________lead(IV) nitrideB. Complete and balance
Solid ReO3 is a material that is an extremely good conductor of electricity. It can be formed by the chemical reaction Re(s) 1 3Re2O7(s) → 7ReO3(s). If 3 mol of Re and 3 mol of Re2O7 are placed in
You perform the hypothetical reaction of an element, X2(g), with another element, Y(g), to produce XY(g).a. Write the balanced chemical equation for the reaction.b. If X2 and Y were mixed in the
A few hydrogen and oxygen molecules are introduced into a container in the quantities depicted in the following drawing. The gases are then ignited by a spark, causing them to react and form H2O.a.
Find the formula weights of the following substances to three significant figures.a. Formaldehyde, CH2Ob. Sulfur dioxide, SO2c. Sodium carbonate, Na2CO3d. Lead(II) phosphate, Pb3(PO4)2
Find the formula weights of the following substances to three significant figures.a. Sulfuric acid, H2SO4b. Phosphorus pentachloride, PCl5c. Ammonium chloride, NH4Cld. Calcium hydroxide, Ca(OH)2
Calculate the mass (in grams) of each of the following species.a. Br atom b. Te atomc. PBr3 molecule d. Fe(OH)2 formula unit
Calculate the mass in grams of the following.a. 0.331 mol Feb. 2.1 mol Fc. 0.034 mol CO2 d. 1.89 mol K2CrO4
Carbon disulfide, CS2, is a colorless, highly flammable liquid used in the manufacture of rayon and cellophane. A sample contains 0.0116 mol CS2. Calculate the mass of carbon disulfide in the sample.
Obtain the moles of substance in the following.a. 7.17 g C b. 4.02 g Cl2c. 78 g C4H10d. 73.5 g Al2(CO3)3
Calculate the following.a. Number of atoms in 25.7 g Alb. Number of atoms in 5.66 g I2c. Number of molecules in 14.9 g N2O5d. Number of formula units in 2.99 g NaClO4e. Number of Ca2+ ions in 4.71 g
Chlorine trifluoride is a colorless, reactive gas used in nuclear fuel reprocessing. How many molecules are there in a 8.55-mg sample of chlorine trifluoride? Mass Percentage
A 1.680-g sample of coal contains 1.584 g C. Calculate the mass percentage of C in the coal.
A 6.01-g aqueous solution of isopropyl alcohol contains 3.67 g of isopropyl alcohol. What is the mass percentage of isopropyl alcohol in the solution?
Ethyl mercaptan is an odorous substance added to natural gas to make leaks easily detectable. A sample of ethyl mercaptan weighing 3.52 mg contains 1.64 mg of sulfur. What is the mass percentage of
Calculate the percentage composition for each of the following compounds (three significant figures).a. NOb. SO3c. NaH2PO3d. Pb(NO3)2
Calculate the percentage composition for each of the following compounds (three significant figures).a. NO2 b. H2N2c. KClO4d. Mg(NO3)2
Which contains more sulfur, 40.8 g of calcium sulfate, CaSO4, or 38.8 g of sodium sulfite, Na2SO3?
Potassium bromate is a colorless, crystalline substance whose composition is 23.4% K, 47.8% Br, and 28.8% O, by mass. What is its empirical formula?
Ethanol, C2H5OH, burns with the oxygen in air to give carbon dioxide and water.C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)What is the amount (in moles) of water produced from 0.77 mol C2H5OH?
Iron in the form of fine wire burns in oxygen to form iron(III) oxide.4Fe(s) + 3O2(g) → 2Fe2O3(s)How many moles of O2 are needed to produce 7.38 mol Fe2O3?
Nitric acid, HNO3, is manufactured by the Ostwald process, in which nitrogen dioxide, NO2, reacts with water.3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g)How many grams of nitrogen dioxide are required in
White phosphorus, P4, is prepared by fusing calcium phosphate, Ca3(PO4)2, with carbon, C, and sand, SiO2, in an electric furnace.2Ca3(PO4)2(s) + 6SiO2(s) + 10C(s) → P4(g) + 6CaSiO3(l) + 10CO(g)How
The following reaction, depicted using molecular models, is used to make carbon tetrachloride, CCl4, a solvent and starting material for the manufacture of fluorocarbon refrigerants and aerosol

Showing 500 - 600 of 1219