SCIN 131 WEEK 4 Exam QUIZ Questions With Answers Latest Graded

SCIN 131 WEEK 4 Exam QUIZ Questions With Answers Latest Graded. A sample of pure lithium carbonate contains 18.8% lithium by mass. What is the % lithium by mass in a sample of pure lithium carbonate that has twice the mass of the first sample?  A. 75.2%  B. 18.8%  C. 9.40%  D. 37.6% Feedback: Mass percent discussed in Chapter 6.2. Question 5 of 25 4.0/ 4.0 Points `I have some aliens in my basement who have developed a chemical weapon in an attempt to escape. I was able to survive the first attack and capture a sample of the dangerous gas. I analyzed it to find that it had a molar mass of 648.52 grams, and its empirical formula is C5H11N2O2P. What is its molecular formula?  A. C20H44N8O8P4  B. C5H11N2O2P  C. C10H22N4O4P2  D. CH2.2N0.4O0.4P0.2  E. cannot be determined from the information given Feedback: Great! Empirical Formula discussed in Chapter 6.2. Question 6 of 25 0.0/ 4.0 Points Since 1983, pennies have been made with zinc and plated with copper. Prior to 1983, pennies were about 95% copper and 5% tin and zinc. However, from , pennies were pure copper. If you had a penny from 1800 that had a mass of 2.78g, how many atoms of copper would you have?  A. 8.13 × 10-26  B. 2.63 × 1022  C. 1.19 × 1026  D. 6.02 × 1023  E. 1.67 x 1024 Feedback: Mass percent discussed in Chapter 6.2. Question 7 of 25 4.0/ 4.0 Points What is the empirical formula for a compound if the compound contains 49.97% carbon, 10.51% hydrogen, and 39.52% fluorine by mass?  A. C2H5F2  B. C2H5F  C. C4H10F2  D. C4H10F4 Feedback: Great! Empirical Formula discussed in Chapter 6.2. Question 8 of 25 4.0/ 4.0 Points `One of the compounds listed below represents an empirical formula. Which one?