Chemistry Online Quiz: Review Semester 1 Use Google Forms to provide answers online to the following questions. 1) What is the correct answer to ( 8.6 + 4.35 ) x 2.99 A) 39 B) 38.5 C) 38.6 D) 38.7 E) 38.9 2) How many significant figures are in the number 0.01250 A) 2 B) 3 C) 4 D) 5 E) 6 Due Date 3) Which of the following is the correct way to express the number 1,868,756 with exactly 3 significant figures? A) 1,870,000. B) 1,900,000 C) 1,869,000 D) 1.87 x 10 6 E) 1.870 x 10 6 4) Ammonia (NH3) is synthesized from nitrogen and hydrogen gas. When the following chemical equation is balanced, what is the sum of all of the coefficients? A) 3 B) 6 C) 7 D) 8 E) None of the above N2 + H2 NH3 5) Which of the following are true about the number of protons in an atom of an element? I. Equal to number of neutrons in an atom II. Equal to number of electrons in an atom III. Determines the elements position on the periodic table D) II and III
6) Which of the following would you expect to have properties most similar to Na. A) K B) Mg C) N D) O E) Ar 7) Which of the following is the most massive? A) One billion carbon atoms B) 0.1 mole of carbon C) 6.0 g of carbon D) 0.1 mole of CO2 E) 5.0 g of CO2 8) Which of the following are true? I. A proton has a mass of about 1800 times the mass of an electron. II. The volume of an atom is mostly empty space where electrons are found. III. The nucleus of an atom is relatively dense. B) III only C) I and II D) I and III 9) Aluminum could achieve a noble gas electron configuration by A) Losing 1 electron B) Gaining 1 electron C) Gaining 3 electrons D) Losing 3 electrons E) Losing 5 electrons 10) Which of the following are true? I. Cations contain more protons than electrons II. Anions contain more protons than electrons III. Ionic compounds are electrically neutral C) I and III D) II and III 11) A compound has an empirical formula of CH2. The molar mass of the compound is 42.09 g/mol. What is the molecular formula of this compound? A) CH2 B) C2H4 C) C2H6 D) C3H6 E) C3H8
12) Find the empirical formula of a compound that contains 1.2 g carbon, 0.20 g hydrogen and 1.6 g oxygen. A) CHO B) CH2O C) C2H2O D) C2HO E) CHO2 13) How many atoms of hydrogen are in 5.0 g of CH4? A) 7.5 x 10 23 atoms H B) 1.9 x 10 23 atoms H C) 4.8 x 10 25 atoms H D) 1.9 x 10 26 atoms H E) 4.7 x 10 22 atoms H 14) A 120.0 g sample of a radioactive isotope has a half-life of 20.0 seconds. What mass of the sample will remain after one minute? A) 120.0 g B) 60.0 g C) 30.0 g D) 15.0 g E) 7.5 g 15) When an ionic bond forms, which of the following is true? D) I and II I. Electrons are shared between two atoms II. Electrons are transferred between two atoms III. Two oppositely charged ions are attracted to each other 16) Which of the following are true? I. Metals typically form cations II. Non-metals typically form cations III. The ionization energy of non-metals is typically greater than the ionization energy of metals. C) I and III D) II and III
17) Which of the following is the electron configuration of a halogen? A) 1s 2 2s 2 2p 6 B) 1s 2 2s 2 2p 6 3s 2 3p 4 C) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 5 D) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 1 E) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5 18) Which of the following are true about electromagnetic radiation? D) I and III I. The frequency of electromagnetic radiation is directly proportional to its energy. II. The wavelength of electromagnetic radiation is directly proportional to its energy. III. All electromagnetic radiation travels at the same speed in a vacuum (3.0 x 10 8 m/s) 19) The chemical formula of magnesium oxalate is MgC2O4. What is the correct chemical formula of sodium oxalate? A) NaC2O4 B) Na2C2O4 C) Na(C2O4)2 D) Na2(C2O4)3 E) NaCO2 20) Which period 3 element could have the following ionization energies, measured in kj/mol? IE1 = 577 IE2 = 1,816 IE3 = 2,881 IE4 = 11,600 A) Na B) Mg C) Al D) Si E) P 21) Which of the following would you expect to most likely form a 2- ion? A) Rb B) Sr C) Sn D) Te E) Xe 22) What is the chemical formula of the compound formed between lithium and selenium? A) LiSe B) LiSe2 C) Li2Se D) Li2Se3 E) Li3Se2
23) What is the correct name of the compound, Cr2(SO4)3? A) Chromium sulfate B) Dichromium trisulfate C) Chromium (II) sulfate D) Chromium (III) sulfate E) Dichromium trisulfur oxide 24) What is the correct chemical formula for manganese (IV) phosphate? A) Mn4PO4 B) Mn4PO3 C) Mn3PO4 D) Mn3(PO4)4 E) Mn4(PO4)3 25) Consider the following atomic radii, measured in picometers. H: 25 Li: 145 Na: 180 K: 220 Rb: 235 Which of the following is a reasonable estimate for the atomic radius of cesium? A) 12 B) 105 C) 225 D) 260 E) 380 26) The number of wave cycles that pass a stationary point per time is called? A) Amplitude B) Wavelength C) Speed D) Frequency E) all of the above 27) Which of the following are TRUE D) I and II I. Electromagnetic radiation is emitted when electrons gain energy II. Electromagnetic radiation is emitted when electrons lose energy III. Electromagnetic radiation is emitted when electrons return to their ground state from an excited state 28) When U-235 undergoes alpha decay, what is remaining isotope? 4 A) 2He 231 B) 90Th 239 C) 94Pu D) 1 0 β 231 E) 90U
29) Which of the following is true about a reaction that releases heat? D) I and II I. The reaction will feel hot to an observer. II. The heat of the reaction will be a negative value. III. The reaction is endothermic 30) What is always true of every endothermic chemical reaction? A) The heat absorbed by the reaction is equal to the heat released by the surroundings. B) The heat absorbed by the reaction is greater than the heat released by the surroundings. C) The heat absorbed by the reaction is less than the heat released by the surroundings. D) The temperature of the surroundings will increase. E) The temperature of the surroundings will not change because of the law of conservation of energy.