CHEM 121 Module 3 Exam Questions and Answers- Portage 2024/2025, Exams of Chemistry

Download CHEM 121 Module 3 Exam Questions and Answers- Portage 2024/2025 and more Exams Chemistry in PDF only on Docsity! M3: Exam - Requires Respondus LockDown Browser + Webcam • Due No due date • Points 100 • Questions 10 • Time Limit 120 Minutes • Requires Respondus LockDown Browser Attempt History Attempt Time Score LATEST Attempt 1 111 minutes 79 out of 100 Score for this quiz: 79 out of 100 Submitted Jan 12 at 3:28pm This attempt took 111 minutes. Question 1 10 / 10 pts You may find the following resources helpful: Scientific Calculator (Links to an external site.) Periodic Table Equation Table Show the calculation of the new volume of a gas sample which has an original volume of 660 ml when collected at 660 mm and 38oC when the pressure increases to 780 mm and the temperature increases to 45oC. Your Answer: 660/1000 = .66L 38+273 = 311K 45+273 = 318k 660mm/760 = 0.8684210526 atm 780mm/760 = 1.026315789 atm pxv/ t = pxv/ t 0.8684210526 X .66 / 311 = 1.026315789 atm x V / 318 0.5731578947/311 = 1.026315789V/318 0.5731578947 x 318 = 1.026315789V x 311 182.2642105 = 319.1842104 V 0.5710314125 L= v .571 L ~ V Question 2 10 / 10 pts You may find the following resources helpful: Scientific Calculator (Links to an external site.) Periodic Table Equation Table nN2 = gN2 / (MWN2) = 7.60 g / 28.02 = 0.2712 mol nO2 = gO2 / (MWO2) = 8.40 g / 32.00 = 0.2625 mol XN2 = 0.2712 / (0.2712 + 0.2625) = 0.5082 XO2 = 0.2625 / (0.2712 + 0.2625) = 0.4918 Question 5 10 / 10 pts You may find the following resources helpful: Scientific Calculator (Links to an external site.) Periodic Table Equation Table Show the calculation of the molecular weight of an unknown gas if the rate of effusion of Neon gas (Ne) is 1.86 times faster than that of an unknown gas. Your Answer: unknown mw = (r^2)(known mw) ne=mw=20.18 (1.86^2)(20.18) (3.4596)(20.18) unknown mw = 69.814728 (rNe /runknown)2 = MWunknown / MWNe (1.86/1)2 = MWunknown / 20.18 MWunknown = (1.86)2 x 20.18 = 69.81 Question 6 7 / 10 pts You may find the following resources helpful: Scientific Calculator (Links to an external site.) Periodic Table Equation Table Write the subshell electron configuration (i.e.1s2 2s2, etc.) for the K19 atom and identify which are valence (outer shell) electrons and determine how many valence electrons there are. Your Answer: K19 4s1 1s2 2s2 2p6 3s2 3p6 4s1 K19 = 19 electrons = 1s2 2s2 2p6 3s2 3p6 4s1 = 1 valence electron determine how many valence electrons there are. Question 7 10 / 10 pts You may find the following resources helpful: Scientific Calculator (Links to an external site.) Periodic Table Equation Table Using up and down arrows, write the orbital diagram for the Ni28 atom and identify which are unpaired electrons and determine how many unpaired electrons there are. Your Answer: Ni281s↑↓2s↑↓2p↑↓↑↓↑↓3s↑↓3p↑↓↑↓↑↓4s↑↓3d↑↓↑↓↑↓↑↑ 1,2 unpaired and its 2 of them Ni28 = 1s2 2s2 2p6 3s2 3p6 4s2 3d8 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ ↑ = 2 unpaired electrons Question 8 10 / 10 pts You may find the following resources helpful: Scientific Calculator (Links to an external site.) Periodic Table Equation Table Write the subshell electron configuration (i.e.1s2 2s2, etc.) for the Ti22 atom and then identify the last electron to fill and write the 4 quantum numbers (n, l, mland ms) for this electron. Your Answer: Ti22 = 1s2 2s2 2p6 3s2 3p6 4s2 3d2 3d2 s-0 p1 d2 f3 *_ *_ _ _ _ -2 -1 0 1 2 n=3 I =2 ml=-1 ms=+1/2 Ti22 = 1s2 2s2 2p6 3s2 3p6 4s2 3d2 : n=3, l=2, ml = -1, ms = +1/2 Question 9 5 / 10 pts You may find the following resources helpful: Scientific Calculator (Links to an external site.) Periodic Table