Classification of Elements and Periodicity Questions and Answers

Calculate the cell potential for the following reaction that takes place in an electrochemical cell at 25°C. Mg(s) | Mg2+ (aq, 2.74 M) Pb2+ (aq, 0.33 M) | Pb(s) Mg2+ (aq) + 2e → Mg(s) E° = -2.37 V E° = -0.13V Pb2+ (aq) + 2e → Pb(s) +2.71 V +2.21 V -1.94 V -2.80 V +2.62 V

Suppose you assumed that the atmospheric pressure was one atmosphere instead of the pressure that you recorded. Describe the error that would occur in reporting the molar mass.

2. a) Draw the Lewis structure of sulfite (SO32-) with minimized formal charges on all atoms and assign partial charges to each atom b) How many electrons is around central S atom? c) What is the hybridization of each atom?

Do atoms generally get bigger or smaller as you go down a group in the periodic table?

"When filling orbitals of equal energy, electrons fill them singly first with parallel spins." This is known as: Bohr's model. Ground state. Hund's rule. Pauli exclusion principle.

Use what you just observed to predict the following. How many drops of water can you put onto a penny before the water spills over the side? How many drops of alcohol before the alcohol spills over the side. Make a prediction, give it a try, and, most importantly, explain what's happening.

Write the complete electron configuration for the vanadium atom. Using NOBLE GAS notation write the electron configuration for the copper atom.

Green light can have a wavelength of 541 nm. The energy of a photon of this light is: 1.07 x 10-^31 J 5.54 x 10^14 J 5.41 x 10^-7 J 2.72 x 10^18 J 3.67 x 10^-19 J

A given set of p orbitals consists of ____ orbitals 1 2 3 4 5

Which of the following groups contains no ionic compounds? PCl5, LiBr, Zn(OH)₂ HCN, NO₂, Ca(NO3)2 CH2O, H,S, NH KOH, CC14, SF4 NaH, CaF2, N₂NH₂

Which of the following statements is (are) true? I. An excited atom can return to its ground state by absorbing electromagnetic radiation. II. The energy of an atom is increased when electromagnetic radiation is emitted from it. III. The energy of electromagnetic radiation increases as its frequency increases. IV. An electron in the n = 4 state in the hydrogen atom can go to the n=2 state by emitting electromagnetic radiation at the appropriate frequency. V. The frequency and wavelength of electromagnetic radiation are inversely proportional to each other. I, II, III II, III, IV I, II, IV III, IV, V III, V

Which of the following describes the compound BaCl₂? Choose all answers that apply. If the compound dissolved in water it would be a strong electrolyte. The compound is ionic. The compound would conduct electricity if molten. The compound is molecular. The compound would be expected to have a relatively low melting point.

(1) What is the name of the element with a valence electron configuration of 3s²3p6? (2) What is the name of the element with a valence electron configuration of 2s²?

(1) What is the element with an electron configuration of 1s²2s²2p63s²3p64s²3d³? (2) What is the element with an electron configuration of 1s²2s²2p63s²3p6?

How many 4d electrons would be predicted in the ground state for the following elements? a. niobium b. silver c. rhenium

Draw the Lewis structure for ICl₂-

Complete and balance the equations for the following reactions. (Use the lowest possible coefficients. Be sure to specify states such as (aq) or (s). If a box is not needed, leave it blank.) K(s) +N₂ (9) ⇒____ K(s) + As(s) ⇒____

What is the correct electron configuration of W²+? [Xe]4f¹45d4 [Xe]4f145d6 [Xe] 6d46s² [Xe]5f¹45d²6s² [Xe] 4f145d652

Determine the formal charge on nitrogen in NO₂. +1 +2 -1 0

A local FM radio station broadcasts at a frequency of 93.8 MHz. Calculate the wavelength at which it is broadcasting. -¹)

(1) What is the complete ground state electron configuration for the silicon atom? (2) What is the complete ground state electron configuration for the vanadium atom?

Draw all resonance structures for the nitric acid molecule, HNO3 (NO₂OH).

(Do not use noble gas notation and enter the subshells in the order in which they are filled. Express your answer as a series of orbitals. For example, the electron configuration of Li would be entered in complete form as 1s²2s¹.) a. Lit b. Tlt c. Br d. I

Draw a Lewis structure for NH4+.

What is the formal charge on each atom in OBr-? A. = -1, Br=0 B. = -1, Br = +1 C. +1, Br = -2 D. O-2, Br = +1 E. = 0, Br = -1

What is the electron-pair geometry for N in NO₂Cl?

Draw all resonance structures for the sulfur trioxide molecule, SO3.

A monatomic ion with a charge of +1 has an electronic configuration of 1s²2s²2p 3s²3p64s²3d¹04p6. This ion is a(n) What is the formula of the ion? What is the chemical symbol of the noble gas this ion is isoelectronic with?

A monatomic ion with a charge of -2 has an electronic configuration of 1s²2s²2p 3s²3p64s²3d¹04p6 This ion is a(n) What is the chemical symbol of the noble gas this ion is isoelectronic with?

a. Give the expected hybridization of the central atom of XeF4. b. Give the expected hybridization of the central atom of SO3.

A. What is the hybridization of the central atom in XeF4? Hybridization = What are the approximate bond angles in this substance ? Bond angles = B. What is the hybridization of the central atom in IBr3? Hybridization = What are the approximate bond angles in this substance ? Bond angles =

9. A water solution of sulfuric acid has a density of 1.67 grams/mL and is 75 percent H₂SO4 by mass. How many moles of H₂SO4 are contained in 400 mL of this solution?

A sample of mercury (II) bromide, HgBr2, weighs 8.65 grams. How many moles are in this sample?

A sample of oxygen gas, O2 weighs 28.4 grams. How many molecules of O2 and how many atoms of O are present in this sample?

a. Identify the element that has atomic nuclei represented by nucleus 1. b. Explain why nucleus 2 and nucleus 4 represent the nuclei of two different isotopes of the same element. c. Identify the nucleus above that is found in an atom that has a stable valence electron configuration.

Calculate ΔH for the reaction: 2NH3 (g) + O2(g) → N₂H₁ (l) + H₂O(l) given the following data: 2NH3(g) + 3N₂O(g) → 4N2 (g) + 3H₂O(l) ΔH-1010kJ N₂O(g) + 3H₂(g) → N₂H4 (1) + H₂O(l) ΔH = -317 kJ N₂H4 (l) + O2(g) → N₂(g) + 2H₂O(l) ΔH=-623 kJ H2(g) + 1/2 O2(g) → H₂O(l) ΔH-286 kJ

Which of the following statements about chemical formulas is FALSE? The subscripts represent the relative mass of each type of atom in the compound. The subscripts do not change for a given compound. The subscripts represent the relative number of each type of atom in the compound. Different compounds made of the same elements have different subscripts.

Does a reaction occur when aqueous solutions of iron(III) sulfate and calcium chloride are combined? yes/no If a reaction does occur, write the net ionic equation.

Methanol (wood alcohol) is a fuel that can be made from biomass (such as cellulose obtained from aspen trees). Methanol can also be made from natural gas. The overall synthesis reaction for the latter case is CH4(g) + H₂O() → CH₂OH(1) + H₂(g), ΔHo = ? Use the reactions below and Hess' law to predict the standard molar enthalpy of synthesis of methanol by this process. CO(g) + 3 H₂(g) -> CH4(g) + H₂O (l) ΔH = -249.9 kJ CO(g) + 2 H₂(g) → CH₂OH (l) ΔH"=-128.7 kJ

The element sodium forms a ____ with the charge ___ The symbol for this ion is ___ and the name is ___ ion. The number of electrons in this ion is ____

Which of the following statements about the mole is FALSE? One mole of water contains 1/2 mole of oxygen atoms. One mole of a monatomic element has a mass equal to its atomic mass expressed in grams. A mole of a monatomic element corresponds to one Avogadro's number of atoms. One mole of atoms makes up an amount of atoms that can be seen with the naked eye.

Consider three 1-L flasks at STP. Flask A contains NH3 gas, flask B contains NO₂ gas, and flask C contains N₂ gas. Which contains the largest number of molecules? Flask C Flask A Flask B All are the same. More information is need to answer this.

A newly discovered gas has a density of 2.33 g/L at 25.0 °C and 709 mm Hg. What is the molar mass of the gas? 61.1 g/mol 5.13 g/mol 805 g/mol 11.3 g/mol

It is desired to inflate a baggie with a volume of 912 milliliters by filling it with neon gas at a pressure of 0.965 atm and a temperature of 309 K. How many grams of Ne gas are needed?

What volume of hydrogen gas is produced when 58.4 g of iron reacts completely according to the following reaction at 25 °C and 1 atm? iron (s) + hydrochloric acid(aq)-iron(II) chloride (aq) + hydrogen(g)

A 5.78 gram sample of neon gas has a volume of 912 milliliters at a pressure of 3.95 atm. The temperature of the Ne gas sample is

The name of the 11th most abundant gas in dry air at sea level is

Which of the following would represent the greatest pressure? 15.5 in Hg 0.660 atm 0379 mmHg 067055 Pa 12.9 psi

A sample of nitrogen gas at a pressure of 0.615 atm and a temperature of 210 °C, occupies a volume of 574 mL. If the gas is cooled at constant pressure until its volume is 485 mL, the temperature of the gas sample will be ___ °C.

A sample of carbon dioxide gas collected at a pressure of 324 mm Hg and a temperature of 284 K has a mass of 54.6 grams. The volume of the sample is ___ L.