General Chemistry 1 PreTest 3 Fall 2022 PDF

General Chemistry 1 PreTest 3 Fall 2022 1. A compound that contains only carbon and hydrogen is 92.2% C and 7.8% H by mass. What is the empirical formula of this substance? a. CH b. CH2 c. C2H2 d. C2H Answer: _____ 2. A compound containing carbon and hydrogen is found to...

General Chemistry 1 PreTest 3 Fall 2022 1. A compound that contains only carbon and hydrogen is 92.2% C and 7.8% H by mass. What is the empirical formula of this substance? a. CH b. CH2 c. C2H2 d. C2H Answer: _____ 2. A compound containing carbon and hydrogen is found to have an empirical formula of CH3. If the molecular mass is about 30.08 g/mole, what is the molecular formula? a. CH3 b. (CH3)2 c. C2H6 d. (CH3)3 e. C3H9 Answer: _____ 3. What is the molarity of H2O in 1.00 L of pure water. Assume water has a density of 1.00 g/mL. Answer: _________ General Chemistry 1 PreTest 3 Fall 2022 4. If you have 50.0 mL of a 10.0 M HNO3(aq) solution, to what final volume must you dilute the solution to obtain a 2.0 M HNO3 (aq) solution? Answer: _________ 5. What is the mass percent of propylene glycol in a 2.500 M solution of propylene glycol (MM=76.09 g/mol) in water? The density of the soluton is 1.030 g/mL. Enter your answer as a percent, not a decimal. Answer: _________ 6. Balance the reaction below and report the value of the coefficient that would appear in front of the O2(g). C2H2(g) + O2(g) CO(g)+ H2O(g) Answer: _________ 7. Who is the spectator ion in the following reaction? Ag+(aq) + NaCl(aq) AgCl(s) + Na+(aq) a. Ag+(aq) b. NaCl(aq) c. AgCl(s) d. Na+(aq) e. Cl-(aq) Answer: _____ General Chemistry 1 PreTest 3 Fall 2022 8. What is the oxidation state of nitrogen in NaNO3? Answer: _________ 9. Given the unbalanced combustion reaction below, who is the reducing agent? C2H2(g) + O2(g) CO(g)+ H2O(g) a. carbon b. hydrogen c. oxygen d. there is no reducing agent in a combustion reaction Answer: _____ 10. Given the reaction below: 2 H2(g) + O2(g) 2 H2O(g) If 8.08 g of H2(g) and an excess of O2(g) react to form 54.06 g of H2O(g), what is the percent yield for this reaction? Enter your answer as a percent, not a decimal. Answer: _________ General Chemistry 1 PreTest 3 Fall 2022 11. The end point in a tritration of a 20.00 mL sample of aqueous HCl was reached by the addition of 15.00 mL of 0.100 M NaOH(aq) as titrant. What is the molarity of the HCl solution in mM? Answer: _________ 12. Given the balanced reaction below: 2 C2H2(g) + 5 O2(g) 4 CO2(g) + 2 H2O(g) If 13.02 g of C2H2(g) is combusted in the presence of excess oxygen, how many grams of CO2(g) will be produced? Answer: _________ 13. What is the pressure, in atmospheres, of two moles of gas at 273.15 K in a container with a volume of 11.2 liters. Answer: _________ 14. What is the pressure, in atmospheres, of two moles of gas at 273.15 K in a container with a volume of 11.2 liters. Answer: _________ General Chemistry 1 PreTest 3 Fall 2022 15. Match each named gas law with the variables it relates ___ 1. Avogadro ___ 2. Boyle ___ 3. Charles a. moles and pressuer b. pressure and volume c. pressure and temperature d. volume and temperature e. moles and volume 16. Match each set of variables with directly proportional or inversely proportional. ___ 1. moles and volume ___ 2. pressure and temperature ___ 3. volume and temperature ___ 4. moles and pressure a. inversely b. directly 17. Given a gas sample is in a sealed container at 2.00 atm and has a volume of 20.5 L at 300.0 K, what will be the volume of the gas at 1.00 atm and 150.0 K? Answer: _________ 18. What is the root mean squared speed of He(g) in this room if the temperature of the room is 30.0 oC? Answer: _________ General Chemistry 1 PreTest 3 Fall 2022 19. What would be the vander Waals' volume (in liters) of a 2.00 mol sample of Cl2(g) at 300.0 K and a vander Waals' pressure of 2.00 atm? For Cl2(g), a = 6.49 L² atm/mol² and b = 0.0652 L/mol. Answer: _________ 20. In the vander Waals equation, which statement is true with respect to the value of the b parameter under conditions of constant temperature and constant moles? a. As the value of the b parameter increases, the pressure will decrease. b. As the value of the b parameter increases, the pressure will increase. c. As the value of the b parameter increases, the vander Waals' volume will beome less than the ideal volume. d. As the value of the b parameter increases, the a parameter must decrease. Answer: _____