CHEMISTRY SCIN 131 Week 4 Quizess | Questions with Correct Solutions

CHEMISTRY SCIN 131 Week 4 Quizess | Questions with Correct Solutions. Eureka! I've discovered a new compound! Yay for me. I have determined that its empirical formula, but in order to determine its actual molecular formula, I need to know which of the following? • A. the number of moles of the compound in a 1.00 g sample of the substance • B. the density of the compound • C. the boiling point and freezing point of the compound • D. the molar mass of the compound. • E. none of these Feedback:Great! Empirical Formula discussed in Chapter 6.2. Question 2 of 25 4.0/ 4.0 Points Dihydrogen monoxide is the formula for a substance that makes up about 60% of the human body. What is mass percent of hydrogen in this compound? • A. 1.01% • B. 10.1% • C. 88.8% • D. 11.2% Feedback:Great! Mass percent discussed in Chapter 6.2. Question 3 of 25 4.0/ 4.0 Points `Before 1982, pennies were made of copper. From 1983 on, they are made of zinc, and only thinly plated with copper. The purity of those pre-1982 pennies are really about 95% copper (5% zinc and tin), but from they were actually pure copper. If you had a penny from 1820 that had a mass of 3.11 grams, how many atoms of copper would you have? • A. 1.97 • B. 6.02 × 1023 • C. 2.95 × 1022 • D. 8.13 × 10-26 • E. 1.19 × 1026 Feedback:Great! Mass percent discussed in Chapter 6.2. Question 4 of 25 4.0/ 4.0 Points `Nicotine (C10H14N2), a member of the nightshade family of plants, is an oily liquid that makes up between 0.6 to 3% of a cigarette's mass. Contact with the liquid pure form can cause death within hours, as nicotine passes through the dermis and heads directly for the bloodstream. Overdoses and death can easily occur in those smoking cigarettes with nicotine patches applied on their body. How many nicotine molecules are in 1.00 g of nicotine? • A. 3.71 x 1021 • B. 9.76 x 1025 • C. 1.02 x 10-26 • D. 2.32 x 1022 Feedback:Great! Mass percent discussed in Chapter 6.2. Question 5 of 25 4.0/ 4.0 Points The empirical formula of an organic molecule is CH; its molar mass is 104.1 g/mol. What is the molecular formula of the molecule? • A. C10H12 • B. C6H6 • C. None of these. • D. C2H4 • E. C8H8 Feedback:Great! Empirical Formula discussed in Chapter 6.2. Question 6 of 25 4.0/ 4.0 Points Salicyclic acid (C7H6O3) is commonly the active ingredient in face washes designed to help with acne. What is the mass percent of carbon in this compound? • A. 60.9% • B. 3.47% • C. 6.09% • D. 34.7% Feedback:Great! Mass percent discussed in Chapter 6.2. Question 7 of 25 4.0/ 4.0 Points `I was wading in the creek and discovered what I thought to be a small meteorite. I took it home and found its mass to be 12.00 kg. I ran some fancy schmancy chemical tests on it, and determined that the mass of nickel within the sample was 300.0 grams. What is the mass percent of nickel in the meteorite? • A. 25.00% • B. 4.000% • C. 2.500% • D. 100.0%