Quiz Questions on Empirical Formulas, Mass Percent, and Chemical Reactions, Exams of Health sciences

Download Quiz Questions on Empirical Formulas, Mass Percent, and Chemical Reactions and more Exams Health sciences in PDF only on Docsity! SCIN131 Week 04 Quiz.Lesson 04 - Week 04 Quiz. Return to Assessment List Part 1 of 3 - 44.0/ 52.0 Points Question 1 of 25 4.0/ 4.0 Points `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 1793-1837 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.  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% Feedback:Great! Mass percent discussed in Chapter 6.2. Question 8 of 25 4.0/ 4.0 Points `A compound known as deuterium oxide, or "heavy water" is sometimes used in nuclear research. It is water, but each hydrogen atom in a "heavy water" molecule has a neutron in the nucleus in addition to the normal proton. So, what would be the percent hydrogen (by mass) in a "heavy water" molecule?  A. 20.1%  B. 79.9%  C. 11.2%  D. 88.8% Feedback:Great! Mass percent discussed in Chapter 6.2. Question 9 of 25 0.0/ 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 5.50 kg. I ran some fancy schmancy chemical tests on it, and determined that the mass of nickel within the sample was 250.0 grams. What is the mass percent of nickel in the meteorite?  A. 0.5454%  B. 0.4545%  C. 4.545%  D. 45.45% Feedback:Mass percent discussed in Chapter 6.2. Question 10 of 25 4.0/ 4.0 Points 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. 37.6%  C. 18.8%  D. 9.40% Feedback:Great! Mass percent discussed in Chapter 6.2. Question 11 of 25 4.0/ 4.0 Points `One of the first chemical WMDs, researchers initially produced VX nerve agent for retail sale in the 1950s as a pesticide. Thankfully, your likelihood of coming in contact with VX is extremely low - the world's stockpiles have been destroyed, including the United States' main stockpile in Anniston, AL. The molecular formula for this nerve agent is C11H26NO2PS, and it has a molar mass of 267.37 g/mol. Given this information, what is its empirical formula? D. C2H3O2  E. C3H4O3 Feedback:Empirical Formula discussed in Chapter 6.2. Part 2 of 3 - Part 02 28.0/ 40.0 Points Question 14 of 25 0.0/ 4.0 Points `Caves form mostly from the reaction of weak carbonic acid (which forms due to carbon dioxide that is in the water) with exposed limestone. What numbers go in the blanks below, in order from left to right, to balance this chemical equation? H2CO3(aq) + CaCO3(s) --> Ca(HCO3)2(aq) + CO2(g) + H2O(l)  A. 2, 1, 1, 3, 1  B. 2, 3, 6, 4, 2  C. 2, 3, 1, 2, 1  D. 3, 1, 1, 2, 2  E. none of the above Feedback:Topic discussed in section 7.1-7.2. Question 15 of 25 4.0/ 4.0 Points Which of the following compounds is soluble?  A. copper carbonate  B. calcium carbonate  C. strontium carbonate  D. sodium carbonate Feedback:Great! Topic discussed in section 7.1-7.2. Use solubility table. Question 16 of 25 4.0/ 4.0 Points `Generally, for a decomp reaction to take place, what else must be added to the reaction?  A. light  B. heat  C. electrical current  D. energy  E. any of the above Feedback:Great! Topic discussed in section 7.1-7.2. Question 17 of 25 0.0/ 4.0 Points `When you are balancing the reaction NO2 + H2O + O2 → HNO3 , what number goes in front of O2?  A. 5  B. 2  C. 3  D. 4  E. 1 Feedback:Topic discussed in section 7.1-7.2. Question 18 of 25 4.0/ 4.0 Points I have the following items in my kitchen. Which one is NOT an acid?  B. ammonium chloride  C. potassium carbonate  D. barium sulfide  E. sodium phosphate Feedback:Great! Topic discussed in section 7.1-7.2. Use solubility table. Question 22 of 25 4.0/ 4.0 Points `I was digging around in the kitchen and came across the following items. Which one is most likely not an acid?  A. lime  B. orange  C. dishsoap  D. vinegar  E. none of these are acids Feedback:Great! Topic discussed in section 7.1-7.2. Question 23 of 25 4.0/ 4.0 Points What numbers, in the correct order from left to right, would go in the blanks in order to balance this equation: Ca3(PO4)2 + H2SO4 → CaSO4(aq) + Ca(H2PO4)2(aq)  A. 1,2,2,1  B. 1,2,1,2  C. 2,1,1,2  D. 2,2,2,2 Feedback:Great! Topic discussed in section 7.1-7.2. Part 3 of 3 - Part 03 4.0/ 8.0 Points Question 24 of 25 4.0/ 4.0 Points `If you weighed out a small sample of lithium acetate, then dumped it into a beaker of water and stirred it around, which of these statements would NOT be true?  A. The the lithium acetate will fail to dissociate  B. The solution will taste salty.  C. The solution will conduct electricity.  D. Individual lithium and acetate ions are present.  E. none of the above Feedback:Great! Electrolytes are discussed in 11.2 Question 25 of 25 0.0/ 4.0 Points 'We discussed how some solutions are electrolytes in this lesson. Which of these would be a strong one?  A. HCl  B. NH4Cl  C. NaC2H3O2  D. NaCl  E. all of the above Feedback:Electrolytes are discussed in 11.2