Grad BIOS 135 Week 2 quiz e Details - All Questions

Grading Summary Grad BIOS 135 Week 2 quiz e Details - All Questions Question 1. Question : (TCO 3) Which of the statements about transition metals is true? Student Answer: Transition metals can gain or lose electrons to form anions or cations. Transition metals can gain a variable number of electrons to form two or more different anions. All transition metals form at least two different ions. All of the above statements None of the above Instructor Explanation: Chapter 4 Points Received: 2 of 2 Comments: Question 2. Question : (TCO 3) Hydrogen combines with oxygen to form water. Which of the statements below best describes the bond that forms between hydrogen and oxygen? Student Answer: It is an ionic bond in which the hydrogen and oxygen atoms are held together by sharing electrons. It is an ionic bond in which the hydrogen atom accepts electrons from the oxygen atom. It is a covalent bond in which the hydrogen atom donates electrons to the oxygen atom. It is a covalent bond in which the hydrogen atom accepts electrons from the oxygen atom. It is a covalent bond in which the hydrogen and oxygen atoms are held together by sharing electrons. Instructor Explanation: Chapter 4 Points Received: 2 of 2 Comments: Question 3. Question : (TCO 3) Which of the following bonds would you predict to be nonpolar covalent? Student Answer: C-P Li-F Br-P Na-Cl S-F Instructor Explanation: See Chapter 4. Atoms with an electronegativity difference of 0.4 or less will form a nonpolar covalent bond. Points Received: 2 of 2 Comments: Question 4. Question : (TCO 3) How many atoms of oxygen are found in a molecule of Zn3(PO4)2? Student Answer: Three Four Seven Eight 10 Instructor Explanation: See Chapter 4. Each PO43- ion has four O atoms. There are two PO43- ions, so there are eight total O atoms. Points Received: 2 of 2 Comments: Question 5. Question : (TCO 3) Rhea has a balloon that contains 0.5 mole of helium. How many particles of helium are in the balloon? Student Answer: 3.01 3.01 × 1022 3.01 × 1023 6.02 × 1023 6.02 × 1022 Instructor Explanation: Chapter 5 Points Received: 2 of 2 Comments: Question 6. Question : (TCO 3) Jackson is performing a chemical reaction in his chemistry lab. He is impatient and wants the reaction to occur more quickly. All of the following would help speed up the reaction, except Student Answer: adding more reactants. increasing the pressure of the reaction. lowering the temperature of the reaction. adding a catalyst. All of the above Instructor Explanation: Chapter 5 Points Received: 2 of 2 Comments: Question 7. Question : (TCO 4) The solute of a solution Student Answer: is never a solid. is the substance present in the smallest concentration. can be a liquid or gas. is a liquid. can be a solid, liquid, or gas. Instructor Explanation: Chapter 6 Points Received: 0 of 2 Comments: Question 8. Question : (TCO 4) Which of the following solutions is isotonic to a red blood cell? Student Answer: Water 2% glucose 10% glucose 0.5% NaCl 0.9% NaCl Instructor Explanation: Chapter 6 Points Received: 2 of 2 Comments: Question 9. Question : (TCO 4) How much 3.00 M CaCl2 solution is required to make 480 mL of a 0.150 M CaCl2 solution? Student Answer: 24.0 mL 9600 mL 216 mL 0.0400 mL 480 mL Instructor Explanation: See Chapter 6. V1C1 = V2C2. V1 × 2.60 M = 480 mL × 0.150 M. V1 = (480 mL × 0.150 M) ÷ 3.00 M = 24.0 mL. Points Received: 2 of 2 Comments: Question 10. Question : (TCO 4) DeShawn has made 0.250 L of a 3.0 M solution of BaSO4. How many moles of BaSO4 are present? Student Answer: 1.3 moles 83 moles 3.0 moles 0.75 mole 750 moles Instructor Explanation: See Chapter 6. (3.0 moles BaSO4/1 L) × 0.250 L = 0.75 moles BaSO4. Points Received: 2 of 2 Comments: Question 11. Question : (TCO 3) Aluminum reacts with sulfuric acid to produce aluminum sulfate and hydrogen gas. The equation for this chemical reaction is shown below. Al + H2SO4 --- Al2(SO4)3 + H2 •Classify the reaction as combination, decomposition, single replacement, or double replacement. (2 points) •Is the equation balanced? If not, balance it. (4 points) •If 1 mole of Al reacted completely, how many moles of Al2(SO4)3 would be produced? How many grams of Al2(SO4)3 would be produced? (4 points) Student Answer: -The reaction is a single replacement -It is not balanced, this is how it should look when balanced: 2 Al + 3 H2SO4 --- Al2(SO4)3 + 3H2 -2 mol Al gives 1 mol Al2(SO4)3, which means that 1 mole of Al gives 0.5 moles of Al2(SO4)3, and 171 grams would be produced. Instructor Explanation: See Chapter 5. •This is a single replacement reaction: A + BC --- AC + B. •The equation is not balanced. The balanced equation is 2Al + 3H2SO4 --- Al2(SO4)3 + 3H2. •2 moles of Al will give 1 mole of Al2(SO4)3. Therefore (1 mole Al) × (1 mole Al2(SO4)3 ÷ 2 mole Al) = 0.5 mole Al2(SO4)3. To find out how many grams this is, multiply 0.5 moles by the molar mass of Al2(SO4)3 (342.15 g/mol). 0.5 mol × 342.15 g/mole = 171.075 g. Points Received: 10 of 10 Comments: