Download Atomic Structure and Periodic Table and more Exams Nursing in PDF only on Docsity!
CHEM 101 FINAL EXAM IVY TECH
EXAM COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) |ALREADY
GRADED A+
If the electron configuration of a ground state sodium atom is 1s22s22p63s1, the electron configuration of the sodium cation (Na+) would be: A. 1s2 2s2 2p6 3s B. 1s2 2s2 2p C. 1s2 2s2 2p6 3s D. 1s1 2s2 2p1 3s1 Correct Answer B Which of the following statements about the quantum- mechanical model is FALSE? A. Orbitals are a probability map of finding electrons. B. Electrons do not behave as particles. C. Orbitals are specific paths electrons follow. D. Electron paths cannot be described exactly. E. All of the above are correct. Correct Answer C An accepted abbreviation format is to write an electron configuration that includes a noble gas symbol in brackets. If you were writing an electron configuration for a bromine atom, which elemental symbol would you place in the bracket?
A. He B. Ne C. Ar D. Kr E. Xe Correct Answer C What is the electron configuration for Kr? A. 1s22s22p63s23p43d104s24p B. 1s22s22p63s23p64s23d24p C. 1s22s22p63s23p64s23d104p D. 1s22s22p63s23p24s23d104p E. none of the above Correct Answer C How many subshells are there in the n=4 principal shell? A. 1 B. 2 C. 3 D. 4 E. Not enough info Correct Answer D Chlorine and bromine have very similar chemical properties. This is best explained by the fact that both elements:
C. 3
D. 4
E. None of the above Correct Answer B How many electrons are in a chlorine atom? A. 1 B. 17 C. 10 D. 7 E. None of the above Correct Answer B When filling orbitals of equal energy, electrons fill them singly first with parallel spins. This is known as: A. Hund's Rule B. Pauli Exclusion Principle C. Bohr's Model D. Ground State E. None of the above Correct Answer A The subshell that has three orbitals and can hold up to six electrons is the: A. S subshell B. P subshell C. D subshell D. F subshell E. None of the above Correct Answer B
When the elements are arranged in order of increasing number of protons, certain sets of properties recur periodically. True False Correct Answer True The early scientists who developed the quantum- mechanical model were bewildered by the model and it altered our fundamental view of matter. True False Correct Answer True The higher the principle quantum number, the lower the orbital energy. True False Correct Answer False When an atom absorbs energy, it often re-emits that energy as heat. True False Correct Answer False The element manganese (Mn) has five valence electrons. True False Correct Answer False
A. -------->
B. <--------
C. <------->
D. = Correct Answer C Consider the Lewis structures for the compound SO3 and the polyatomic ions SO32- and SO42-. Which of these must exist as a set of resonance structures? A. SO3 only B. SO32- only C. SO42- only D. all of these show resonance E. none of these show resonance Correct Answer A What is the molecular geometry if you have 3 single bonds and 1 lone pair around the central atom? A. bent B. linear C. tetrahedral D. trigonal pyramidal E. not enough info Correct Answer D What is the molecular geometry of SiH4? A. bent B. linear C. tetrahedral D. trigonal pyramidal E. not enough info Correct Answer C
Which of the following statements about the water molecule is TRUE? A. A water molecule has two dipole moments and they cancel each other. B. A water molecule is symmetrical and therefore is non- polar. C. A water molecule is asymmetric and therefore is polar. D. The electronegativities of hydrogen and oxygen are equal and therefore a water molecule is non-polar. E. None of the above Correct Answer C Consider the following electronegativity values: H=2.1, Cl=3.0, F=4. Which molecule below would you expect to have the more polar bond? A. H B. Cl C. F D. HCl E. HF Correct Answer E Which of the following statements are TRUE about the BF3 molecule? A. BF3 has a trigonal planar molecular geometry B. BF3 violates the octet rule for the central atom C. BF3 is nonpolar
A. 8
B. 26
C. 29
D. 32
E. none of the above Correct Answer D Which molecule listed below has a polar covalent bond? A. NaCl B. H2O C. H D. all of the compounds E. none of the compounds Correct Answer B A correct Lewis structure of an atom of carbon would have eight dots surrounding the symbol of the element True False Correct Answer False Resonance structures are the best representation we can draw but do not accurately reflect the true structure. True False Correct Answer True Having eight valence electrons is very stable and is called an octet. True False Correct Answer True
A chemical bond is classified as a covalent bond if it involves the transfer of electrons. Correct Answer False Lewis structures only use the valence electrons in determining the bonding. True False Correct Answer True Diatomic O2 can react with the element magnesium to form magnesium oxide (MgO). The balanced chemical equation is: O2 + Mg ⟶ 2 MgO If 4 moles of magnesium totally reacted with more than enough O2, how many moles of MgO would be expected to form? A. 8 Moles B. 2 Moles C. 4 Moles D. 1 Mole E. Not Enough Info Correct Answer C Which of the following is TRUE? A. Stoichiometry allows prediction of how much of the reactants are necessary to form a given amount of product.
A. 0.
B. 9.
C. 5.
D. 15.45 Correct Answer B Calculate the maximum number of grams of NH3 that can be produced by the reaction of 2.00 g of N2 with 3.00 g of H2. Reaction: N2 (g) + 3H2 (g) ⟶ 2 NH3 (g) A. 2. B. 0. C. None of the above D. 4. E. 17.0 Correct Answer A Which is the limiting reactant in the following reaction given that you start with 42.0 g of CO2 and 99.9 g KOH? Reaction: CO2+ 2 KOH ⟶ K2CO3 + H2O A. CO B. Not enough information C. KOH D. K2CO E. H2O Correct Answer C How many moles of lithium nitrate are theoretically produced if we start with 3.4 moles of Ca(NO3)2 and 2. moles of Li3PO4?
Reaction: 3 Ca(NO3)2 + ⟶ 6LiNO3 + Ca3(PO4) A. 1. B. 6. C. 1. D. Not enough info E. 7.2 Correct Answer B Consider the following reaction: 2 Mg + O2 ⟶ 2 MgO Δ Hrxn = - 1203 kJ. Calculate the amount of heat (in kJ) associated with complete reaction of 4 moles of Mg. A. - 1203 kJ B. - 601.5 kJ C. - 4812 kJ D. None of the above E. - 2406 kJ Correct Answer E Hydrochloric acid reacts with barium hydroxide according to the equation: 2 HCl (aq) + Ba(OH)2 (aq) ⟶ BaCl2 (aq) + 2 H2O ( l) Δ H= - 118 kK Calculate the heat (in kJ) associated with the complete reaction of 18.2 grams of HCl (aq). A. - 58. B. - 29. C. None of above
B. 1.
C. 4.
D. 1.
E. 2.2 Correct Answer E How many moles of chlorine gas are needed to make 0. moles of sodium chloride? Given the reaction: 2 Na + Cl2 ⟶ 2NaCl A. 3. B. 0. C. 1. D. 0. E. Not enough info Correct Answer B How many moles of NH3 can be produced by the reaction of 2.00 g of N2 with 3.00 g H2? Reaction: N2 (g) + 3 H2 (g) ⟶ 2 NH3 (g) A. 1. B. 0. C. 0. D. 0. E. None of the above Correct Answer C The reaction of one mole of nitrogen gas with three moles of hydrogen gas releases 92 kJ of thermal energy to the surroundings. Which of the following is TRUE?
A. None of the above are true B. This reaction is exothermic C. This reaction has a negative enthalpy of reaction D. All of the above are true E. Complete reaction of two moles of nitrogen gas would release 184 kJ of thermal energy in this reaction. Correct Answer D If the theoretical yield of a reactant is 144 grams and the actual yield of the reaction is 72 grams, the percent yield of the reaction is 200%. True False Correct Answer False Given the following generic equation, 2A +3B ⟶ A2B3 Δ Hrxn = +444 kJ, if you completely reacted 1 mole of compound A, the amount of heat absorbed would be 222 kJ. True False Correct Answer True The limiting reactant is not necessarily the reactant with the least mass. True False Correct Answer True
E. None of the above Correct Answer A How many electrons are unpaired in the orbitals of nitrogen? A. 14 B. 5 C. 9 D. 3 E. None of the above Correct Answer D What is the volume of 28.0g of nitrogen gas at STP? A. 33.6 L B. 11.2 L C. 22.4 L D. 44.8 L E. none of the above Correct Answer C Hydrogen gas produced in the laboratory by the reaction of zinc and hydrochloric acid was collected over water at 25C. The barometric pressure at the time was 742.5 mm Hg. What is the pressure of dry hydrogen gas if the vapor pressure of water at 25C is 23.8 mm Hg? A. 742.5 mmHg B. 718.7 mmHg C. 766.3 mmHg D. 760.0 mmHg E. None of the above Correct Answer B
Charle's Law is expressed as: A. V is proportional to 1/P B. P is proportional to V C. V is proportional to 1/T D. V is proportional to T E. none of the above Correct Answer D 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. 1,329 atm B. 17.5 cm Hg C. 639 torr D. 1.75 atm E. none of the above Correct Answer D A sample of helium gas initially at 37.0C, 785 torr and 2. L was heated to 58.0C while the volume expanded to 3. L. What is the final pressure in atm? A. 517 B. 0. C. 1. D. 3. E. none of the above Correct Answer B How many liters of O2 (g) are needed to react completely with 56.0 L of CH4 (g) at STP to produced CO2 (g) and H2O (g)?
