Chemistry Questions With Correct Answers 2022

Chemistry Questions With Correct Answers 2022 1. Carbon-12 and carbon-14 are isotopes. What do they have in common? A. Number of nuclear particles B. Number of protons C. Number of neutrons D. Mass number - Correct ...

Chemistry Questions With Correct Answers 2022 1. Carbon-12 and carbon-14 are isotopes. What do they have in common? A. Number of nuclear particles B. Number of protons C. Number of neutrons D. Mass number - Correct Answer- B. Number of protons 2. A substance with a pH of 3 is how many times more acidic than a substance with a pH of 5? A. 8 B. 2 C. 100 D. 1,000 - Correct Answer- C. 100 The pH scale is a logarithmic scale. Therefore each number on the pH represents a tenfold increase or decrease in acidity. In this example, a difference in pH of 2 equals a 10 times 10, or 100 times increase in acidity; 10 x 10 = 100 3. Radioactive isotopes are frequently used in medicine. What kind of half-life would a medical isotope probably have? A. Seconds long B. Days long C. Year long D. Many years long - Correct Answer- B. Days long 4. When an acid is added to a base, water and a salt form. What kinds of bonds form in these two compounds? A. Liquid and metallic B. Polar and nonpolar covalent C. Polar covalent and ionic D. Ionic only - Correct Answer- C. Polar covalent and ionic 5. Al(NO3)3 + H2SO4 → Al2(SO4)3 + HNO3 is an example of which kind of reaction? A. Decomposition reaction B. Synthesis reaction C. Single replacement reaction D. Double replacement reaction - Correct Answer- D. Double replacement reaction 6. B, Si, As, Te, At, Ge, and Sb form a staircase pattern on the right side of the periodic table. How can these elements be classified? A. As metals B. As semimetals C. As nonmetals D. As ultrametals - Correct Answer- B. As semimetals (Metalloids) 7. If gas A has four times the molar mass of gas B, you would expect it to diffuse through a plug ___________. A. at half the rate of gas B B. at twice the rate of gas B C. at a quarter the rate of gas B D. at four times the rate of gas B - Correct Answer- A. at half the rate of gas B M1 = 1 M2 = 4 4/1 = 2/1 (half) 8. Which of the following is not an allotrope of carbon? A. Diamonds B. Graphite C. Fluorine D. Buckminsterfullerene - Correct Answer- C. Fluorine (atomic element) 9. Which of these factors would not affect rates of reaction? A. Temperature B. Surface area C. Pressure D. Time - Correct Answer- D. Time 10. You would expect an amino acid to contain which two functional groups? A. R-NH2 and R-COOH B. R-CHO and R-CO-NH2 C. R-OH and R-COOR D. R-O-R and R-COOH - Correct Answer- A. R-NH2 and R-COOH 11. What is the coefficient of O2 after the following equation is balanced? A. 1 B. 2 C. 3 D. 4 - Correct Answer- B. 2 Examination of the first substance shows that methane gas has one carbon atom. There is also one carbon atom on the right side of the equation, so there is no need to balance this. There are four hydrogen atoms on the left side. To balance this, change the coefficient on the right side so that there are four hydrogen atoms there as well: ___CH4 + ____O2 ---> ____CO2 + ____H2O Now there are two atoms of oxygen on the left and four on the right (two from carbon dioxide and two from water). To balance, change the coefficient on the left to 2: 1CH4 + 2O2 ---> 1CO2 + 2H2O 12. Which element would you expect to be least reactive? A. Li B. Cr C. Nd D. Xe - Correct Answer- D. Xe (noble gas) 13. Which is a property of an ionic compound? A. Low melting point B. Poor conductivity C. Shared electrons D. Crystalline shape - Correct Answer- D. Crystalline shape Ionic compounds have high melting points, good connectivity, and a crystalline shape. An example is table salt, NaCl. 14. How many neutrons are in an atom of uranium-235? A. 92 B. 125 C. 143 D. 235 - Correct Answer- C. 143 (Protons of uranium is 92) 235-92=143 15. What is the correct electron configuration for lithium (atomic number is 3)? A. 1s22s1 B. 1s22s2 C. 1s22s12p1 D. 1s12s12p2 - Correct Answer- A. 1s22s1 16. The molar mass of glucose is 180.0 g/mol. If an IV solution contains 5 g glucose in 100 g water, what is the molarity of the solution? A. 0.28M B. 1.8M C. 2.8M D. 18M - Correct Answer- A. 0.28M To perform this operation, you must know the number of moles of solute and the number of liters of solution, because molarity equals moles/liter. 100 grams of solution = 0.1 liters of solution. 5 grams of solute where the molar mass of the solute is 180.0 g/mol means a molarity of 5/180 = 0.027777 = 0.028/0.1=0.28 17. Which ion would you expect to dominate in water solutions of bases? A. MgCl2 B. 2HCl C. H+ D. OH- - Correct Answer- D. OHfor acid solutions: [H+] > [OH-] for basic solutions: [H+] < [OH-] for neutral solutions or for pure water: [H+] = [OH-] 18. To the nearest whole number, what is the mass of one mole of water (H2O)? A. 16 g/mol B. 18 g/mol C. 20 g/mol D. 22 g/mol - Correct Answer- B. 18 g/mol So, one mole of H2O has a mass in grams equal to the atomic weight of two atoms of hydrogen plus one atom of oxygen - about 1 + 1 + 16 or 18 g. 19. What is the charge of an alpha particle? A. -1 B. +1 C. +2 D. No charge - Correct Answer- C. +2 20. What is the correct name of AgNO3? A. Argent nitrous B. Argent oxide C. Silver nitrite D. Silver nitrate - Correct Answer- D. Silver nitrate 21. What is the oxidation state of the chlorine atom in the compound HCl? A. +1 B. -1 C. +2 D. -2 - Correct Answer- B. -1 22. Which of these types of intermolecular force is strongest? A. Dipole-dipole interaction B. London dispersion force C. Keesom interaction D. Hydrogen bonding - Correct Answer- D. Hydrogen bonding 23. A salt (NaCl) solution has a molarity of 1.5 M. How many moles of this salt are present in 2.0 L of this solution? A. 0.75 B. 1.5 C. 2.0 D. 3.0 - Correct Answer- D. 3.0 1.5 x 2.0 = 3.0 24. What is the correct formula for silver hydroxide? A. AgO2 B. AgOH C. AgOH2 D. AgH2O - Correct Answer- B. AgOH 25. Which gives the number of protons in the atomic nucleus of an alkali metal? A. 9 B. 10 C. 11 D. 12 - Correct Answer- C. 11 1. The energy required to remove the outermost electron from an atom is called __________. A. covalent bonding B. electronegativity C. atomic radius D. ionization energy - Correct Answer- D. ionization energy 2. In the presence of an acid, what color is phenolphthalein? A. Clear B. Blue C. Pink D. Red - Correct Answer- A. Clear in the presence of a base it will turn magenta 3. Fifty-six kg of a radioactive substance has a half-life of 12 days. How many days will it take the substance to decay naturally to only 7 kg? A. 8 B. 12 C. 36 D. 48 - Correct Answer- C. 36 56 --1--> 28 --2--> 14 --3--> 7 3 x 12 = 36 4. Which compound contains a polar covalent bond? A. O2 B. F2 C. Br2 D. H2O - Correct Answer- D. H2O 5. AB --> A + B represents what type of chemical reaction? A. Synthesis B. Decomposition C. Single replacement D. Double replacement - Correct Answer- B. Decomposition 6. Among the following elements, which is a nonmetal? A. Mercury B. Magnesium C. Sulfur D. Potassium - Correct Answer- C. Sulfur 7. You contain two odorous gases in vials with porous plugs. Gas A has twice the mass of Gas B. Which observation is most likely? A. You will smell Gas A before you smell Gas B. B. You will smell Gas B before you smell Gas A. C. You will smell Gas A but not Gas B. D. You will smell Gas B but not Gas A. - Correct Answer- B. You will smell Gas B before you smell Gas A. the gas with less mass would be smelled sooner 8. The three important allotrophic forms of phosphorus are red, white, and __________. A. green B. gray C. black D. silver - Correct Answer- C. black 9. Here are the solubilities of four substances at 0°C, in grams of solute per 100 mL of water. Solid citric acid 49 Solid potassium phosphate 44 Gaseous nitrogen 0.0030 Gaseous oxygen 0.0070 If the temperature increases to 20°C, what would you expect to happen to the solubility figures? A. Citric acid and potassium phosphate will decrease; nitrogen and oxygen will increase. B. Citric acid and potassium phosphate will increase; nitrogen and oxygen will decrease. C. All four figures will increase. D. All four figures will decrease. - Correct Answer- B. Citric acid and potassium phosphate will increase; nitrogen and oxygen will decrease. 10. What is the name of the compound CH3-CH2-CH2-CH3? A. Cyclobutane B. Butane C. Butene D. Butyne - Correct Answer- B. Butane 11. When balanced, the reaction Fe + O2 --> Fe2O3 will be - Correct Answer12. Which two elements are most alike in reactivity? A. He and H B. K and Ar C. Cl and P D. Ba and Mg - Correct Answer- D. Ba and Mg (same column/group) 13. How many electrons are shared in a single covalent bond? A. 1 B. 2 C. 3 D. 4 - Correct Answer- B. 2 14. How many neutrons are in an atom of carbon-12? A. 2 B. 4 C. 6 D. 24 - Correct Answer- C. 6 (atomic number of carbon is 6) 12-6 = 6 15. What is the correct electron configuration for magnesium? A. 1s22s2 B. 1s22s22p6 C. 1s22s22p63s2 D. 1s22s22p63s23p1 - Correct Answer- C. 1s22s22p63s2 (Mg has an atomic number of 12) 16. What is the molarity of a solution containing 0.45 moles of NaCl in 4 liters? A. 0.11 M NaCl B. 0.45 M NaCl C. 1.8 M NaCl D. 8.9 M NaCl - Correct Answer- A. 0.11 M NaCl 0.45/4 = 0.1125 17. Where would you expect tap water to fall on the pH scale? A. Between 1 and 3 B. Between 4 and 6 C. Between 6 and 8 D. Between 8 and 10 - Correct Answer- C. Between 6 and 8 tap water is relatively neutral 18. To the nearest whole number, what is the mass of one mole of sodium chloride? A. 36 g/mol B. 43 g/mol C. 58 g/mol D. 72 g/mol - Correct Answer- C. 58 g/mol Na - 23 Cl - 35 23 + 35 = 58 19. What form of radiation is composed of electrons traveling at around 16,000 km/sec? A. Alpha radiation B. Beta radiation C. Gamma radiation D. Delta radiation - Correct Answer- A. Alpha radiation beta - 130,000 km/sec 20. What is the correct name of ZnSO4? A. Zinc sulfate B. Zinc sulfide (ZnS) C. Zinc sulfur D. Zinc oxide (ZnO) - Correct Answer- A. Zinc sulfate 21. What is the oxidation state of the oxygen atom in the compound NaOH? A. -2 B. -1 C. 0 D. +2 - Correct Answer- A. -2 22. Which of these intermolecular forces would have the lowest boiling point? A. Dipole-dipole interaction B. London dispersion force C. Keesom interaction D. Hydrogen bonding - Correct Answer- B. London dispersion force 23. Concentrated HCl has a molarity of 12.0. What volume of concentrated HCl should be used to prepare 500 mL of a 3.00 M HCl solution? A. 75 mL B. 100 mL C. 125 mL D. 150 mL - Correct Answer- C. 125 mL 500/12.0 = 41.66 x 3 = 125 24. What is the correct formula for potassium chloride? A. NaCl B. KCl C. KCl2 D. ClK - Correct Answer- B. KCl 25. Which of these elements has the greatest atomic mass? A. Au B. Ba C. I D. W - Correct Answer- A. Au 1. Aluminum (Al) has 13 protons in its nucleus. What is the number of electrons in an Al3+ ion? A. 16 B. 13 C. 10 D. 3 - Correct Answer- C. 10 +3 - atom lost 3 electrons 13-3=10 2. Blood with a pH of 1.3 indicates what about the blood sample? A. It is strongly acidic. B. It is strongly basic. C. It is weakly acidic. D. It is weakly basic. - Correct Answer- A. It is strongly acidic. 3. A radioactive isotope has a half-life of 20 years. How many grams of a 6-gram sample will remain after 40 years? A. 8 B. 6 C. 3 D. 1.5 - Correct Answer- D. 1.5 6 - 3 - 1.5 4. Which compound has a nonpolar bond in which the electrons are shared equally? A. H2O B. NH3 C. Cl2 D. CH4 - Correct Answer- C. Cl2 5. Name the reaction shown: 8Fe + S8 --> 8FeS A. Single displacement B. Double displacement C. Synthesis D. Acid-base - Correct Answer- C. Synthesis 6. In the solid state, you would expect a nonmetal to be __________. A. brittle B. lustrous C. malleable D. conductive - Correct Answer- A. brittle 7. The molar mass of some gases is as follows: carbon monoxide—28.00 g/mol helium—4.00 g/mol nitrogen—14.01 g/mol oxygen—16.00 g/mol Which would you expect to diffuse most rapidly? A. Carbon monoxide B. Helium C. Nitrogen D. Oxygen - Correct Answer- B. Helium a gas with lower mass will diffuse more rapidly 8. Which is a triatomic allotrope of oxygen? A. Ozone B. Water C. Acidic oxide D. Carbon dioxide - Correct Answer- A. Ozone 9. Which substance shows a decrease in solubility in water with an increase in temperature? A. NaCl B. O2 C. KI D. CaCl2 - Correct Answer- B. O2 10. What is the product of combustion of a hydrocarbon in excess oxygen? A. Carbon dioxide and water B. Naphthalene C. Chlorine and bromine D. Carbonium ions - Correct Answer- A. Carbon dioxide and water 11. Balance this equation: Zn + HCl --> ZnCl2 + H2 - Correct Answer12. On the periodic table, where are atoms with the largest atomic radius located? A. At the top of their group B. In the middle of their group C. At the bottom of their group D. Along the right-hand side - Correct Answer- C. At the bottom of their group 13. Which of the following compounds is ionic? A. NaCl B. H2O C. HCl D. NH4 - Correct Answer- A. NaCl (metal and non metal) 14. How many electrons are in a neutral atom of neon (Ne)? A. 9 B. 10 C. 11 D. 12 - Correct Answer- B. 10 15. What is the correct electron configuration for carbon? A. 1s22s22p1 B. 1s22s22p2 C. 1s22s22p3 D. 1s22s22p63s1 - Correct Answer- B. 1s22s22p2 (atomic number of C is 6) 16. A chemist takes 100 mL of a 0.40 mL NaCl solution. She then dilutes it to 1L. What is the concentration (molarity) of the new solution? A. 0.04 M NaCl B. 0.25 M NaCl C. 0.40 M NaCl D. 2.5 M NaCl - Correct Answer- A. 0.04 M NaCl 100 mL = 0.1 = 1/10 0.40/10 = 0.04 17. A drop of one of these substances rapidly turns litmus dye from blue to red. What substance is it? A. Milk B. Sea water C. Ammonia D. Lemon juice - Correct Answer- D. Lemon juice 18. To the nearest whole number, what is the mass of one mole of hydrogen chloride? A. 36 g/mol B. 38 g/mol C. 71 g/mol D. 74 g/mol - Correct Answer- A. 36 g/mol (H - 1.008/ Cl - 35.45) HCl = 1 + 35 = 36 19. What is the charge of a gamma ray? A. -1 B. +1 C. +2 D. No charge - Correct Answer- D. No charge 20. What is the correct name of MgO? A. Manganese oxide B. Magnesium oxide C. Magnesium oxate D. Magnesium hydroxide - Correct Answer- B. Magnesium oxide 21. What is the oxidation state of the nitrogen atom in the compound NH3? A. -3 B. -1 C. +1 D. +3 - Correct Answer- A. -3 22. Which of these intermolecular forces might represent attraction between atoms of a noble gas? A. Dipole-dipole interaction B. London dispersion force C. Keesom interaction D. Hydrogen bonding - Correct Answer- B. London dispersion force 23. If 58.5 g of NaCl (1 mole of NaCl) are dissolved in enough water to make 0.500 L of solution, what is the molarity of the solution? A. 1.0 M B. 2.0 M C. 11.7 M D. The answer cannot be determined from the information given. - Correct AnswerB. 2.0 M 1.0 / 0.500 = 2.0 24. What is the correct formula for sodium nitrate? A. Na2NO B. Na3NO C. NaNO2 D. NaNO3 - Correct Answer- D. NaNO3 25. Why does fluorine have a higher ionization energy than oxygen? A. Fluorine has a smaller number of neutrons. B. Fluorine has a larger number of neutrons. C. Fluorine has a smaller nuclear charge. D. Fluorine has a larger nuclear charge. - Correct Answer- D. Fluorine has a larger nuclear charge. Sodium's ground state electron configuration may be represented as 1s22s22p63s. How many energy levels does sodium have? A. 1 B. 2 C. 3 D. 6 - Correct Answer- C. 3 The first energy level of any atom contains just an s subshell. The second may include an s and a p subshell. Looking at sodium in table form may make this easier to solve: 1s2 2s22p6 3s 2+2+6+1 = 11 What is the expected pH of orange juice? A. Between 3.0 and 4.0 B. Between 6.0 and 7.0 C. Between 8.0 and 9.0 D. Between 11.0 and 12.0 - Correct Answer- A. Between 3.0 and 4.0 How does a change in the reaction temperature increase the rate of a chemical reaction? A. Decreasing the temperature increases the concentration of reactants. B. Decreasing the temperature increases the number of collisions between reactants. C. Increasing the temperature increases the activation energy of the reaction. D. Increasing the temperature increases the kinetic energy of the reactants. - Correct Answer- D. Increasing the temperature increases the kinetic energy of the reactants. What type of bond involves the transfer of electrons between metal and nonmetal ions with opposite charges? A. Ionic B. Dipole-dipole C. Intermolecular D. Covalent - Correct Answer- A. Ionic What determines the oxidation state of a molecule? A. The number of hydrogen atoms B. The sum of its charges C. The number of oxygen atoms D. The sum of protons and neutrons - Correct Answer- B. The sum of its charges Which of the following describes an acid? A. It turns litmus paper blue. B. It denatures proteins. C. It has a pH higher than 7. D. It donates protons. - Correct Answer- D. It donates protons. According to the reaction 2NO + O2 → NO2, how many moles of oxygen are needed to react with 6 moles of nitric oxide? A. 2 B. 3 C. 4 D. 6 - Correct Answer- B. 3 Which generic equation is an example of a synthesis reaction? A. A + B → AB B. AB → A + B C. AB + CD → AD + BC D. A + BC → AC + B - Correct Answer- A. A + B → AB What end product of metabolism is responsible for muscle cramping that occurs during strenuous exercise? A. ATP B. Carbon dioxide C. Lactate D. Pyruvate - Correct Answer- C. Lactate How many milligrams are in 0.025 grams?...