FINAL 07 2020, questions and answers PDF

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Module_1_ Ch_03...

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6/13/2020

Module #1: Ch 03

Module #1: Ch 03 Due: 11:59pm on Thursday, July 1, 2021 You will receive no credit for items you complete after the assignment is due. Grading Policy

Activity: The Polarity of Water

Click here to complete this activity. Then answer the questions.

Part A Each water molecule is joined to _____ other water molecules by ____ bonds. ANSWER:

four ... hydrogen two ... hydrogen three ... ionic four ... polar covalent two ... polar covalent

Correct As can be seen in the illustration on page 1 of the activity titled "The Polarity of Water" a water molecule is joined to four other water molecules by hydrogen bonds.

Part B The unequal sharing of electrons within a water molecule makes the water molecule _____. ANSWER:

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Module #1: Ch 03

polar hydrophobic ionic change easily from a liquid to gaseous form have a low surface tension

Correct The electrons spend more time with the oxygen of the water molecule than with the hydrogens of water. Thus, the oxygen has a net negative charge and the hydrogens have a net positive charge.

Part C The tendency of an atom to pull electrons toward itself is referred to as its _____. ANSWER:

electronegativity polarity covalency ionic potential tonicity

Correct The question defines electronegativity.

Part D In this molecule, what type of bond is found between the oxygen and hydrogens?

ANSWER:

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Module #1: Ch 03

hydrophobic hydrophilic ionic polar covalent nonpolar covalent

Correct While oxygen shares electrons with hydrogen, the electrons spend more time with the oxygen than with the hydrogens.

Part E Which of these bonds is weakest? ANSWER:

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Correct Hydrogen Bonds are weaker than covalent bonds because they do not involve sharing of electrons, and they are weaker than ionic bonds because they involve the attraction of partial (not full) opposite charges.

Part F Why isn't this insect drowning?

ANSWER:

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Module #1: Ch 03

The insect is flying just above the water surface. The insect is swimming. It is difficult to change the temperature of water. The insect is very light. Surface tension.

Correct The high surface tension of water allows the insect to remain on the surface.

Activity: Cohesion of Water

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Part A What process is illustrated by this animation? To view the animation, click here. Then click on the image to start the animation. What process is illustrated by this animation? ANSWER:

antigravity evaporation gravity precipitation push

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Module #1: Ch 03

Correct Water is moving up the tree as it evaporates from the leaf surface.

Chapter 3 Pre-Lecture Question 3 Part A The amount of energy that must be absorbed or lost to raise or lower the temperature of 1 g of liquid water by 1°C _____.

Hint 1. Consider the specific heat of water.

ANSWER: is 1,000 joules is 1 kilocalorie is 1,000 kilocalories is 1 calorie is 1,000 calories depends on the initial temperature of the water sample

Correct The specific heat of water is 1 calorie or 4.18 Joules.

Activity: Acids, Bases, and pH

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Module #1: Ch 03

Part A What is the arrow pointing to?

ANSWER:

electron water molecule hydronium ion hydrogen ion hydroxide ion

Correct The arrow is indicating a single proton, a hydrogen ion (H+).

Part B What is the arrow pointing to?

ANSWER:

water hydroxide ion hydrogen ion proton hydronium ion

Correct The arrow is indicating a hydroxide ion (OH-).

Part C https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245851

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Module #1: Ch 03

In a neutral solution the concentration of _____. ANSWER:

hydrogen ions is greater than the concentration of hydroxide ions hydrogen ions is equal to the concentration of hydroxide ions water molecules is less than the concentration of hydrogen ions water molecules is less than the concentration of hydroxide ions hydrogen ions is less than the concentration of hydroxide ions

Correct This is the definition of a neutral solution.

Part D How does the pH of the solution on the right compare with that of the solution on the left?

ANSWER:

The solution on the right is acidic relative to the solution on the left. Both of these solutions are equally acidic. The solution on the right is basic relative to the solution on the left. Both of these solutions are equally basic. The solution on the right is neutral relative to the solution on the left.

Correct The solution on the right has a lower concentration of hydrogen ions relative to hydroxide ions than does the solution on the left.

Activity: Dissociation of Water Molecules

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Module #1: Ch 03

Click here to complete this activity. Then answer the questions.

Part A What name is given to this molecule?

ANSWER:

methane glucose water hydronium ion hydroxide ion

Correct A water molecule that gains a hydrogen becomes a hydronium ion.

Part B How did this molecule form?

ANSWER:

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Module #1: Ch 03

A water molecule split in half. Two water molecules bonded. Evaporation. A hydrogen molecule bonded with an OH- molecule. A water molecule gained an hydrogen ion from another water molecule.

Correct This molecule was formed by the transfer of a hydrogen ion from one water molecule to another.

Part C What name is given to this molecule?

ANSWER:

glucose hydroxide ion hydronium ion water DNA

Correct A water molecule that loses a hydrogen ion is referred to as a hydroxide ion.

Part D This animation illustrates the _____ of water. To view the animation, click here. Then click on the image to start the animation. ANSWER:

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Module #1: Ch 03

specific heat cohesion adhesion dissociation surface tension

Correct The transfer of a hydrogen atom from one water molecule to another is referred to as dissociation.

Part E Which of these is the correct equation for the dissociation of water? ANSWER:

H2O H+ + OHH2O + H2O+ H2O + OHH+ H2O + H2O+ H2O + H2O H3O+ + OHH2O + OH- H2O+

Correct This is the correct equation for the dissociation of water molecules.

Part F What is the charge on a hydronium ion? ANSWER:

12+ 0 21+

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Module #1: Ch 03

Correct The formation of hydronium results in the gain of 1 more proton than electron.

Part G What is the charge on a hydroxide ion? ANSWER:

1+ 2+ 120

Correct A hydroxide ion is formed when a water molecule loses a hydrogen ion.

Part H About _____ molecules in a glass of water are dissociated. ANSWER: 1 in 2 1 in 1,000,000,000 1 in 500,000,000 1 in 5,000,000 1 in 1,000,000

Correct One in half a billion.

Chapter 3 Pre-Lecture Question 10 Part A Most acid precipitation results from the combination of _____ with water in the atmosphere, forming strong acids that fall with rain or snow. https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245851

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Module #1: Ch 03

Hint 1. Consider which of these substances would form a strong acid when dissolved in water.

ANSWER:

sulphur oxides and nitrogen oxides ammonium carbon dioxide buffers ozone

Correct These compounds react with water in the atmosphere to form sulphuric acid and nitric acid.

Score Summary: Your score on this assignment is 95.1%. You received 17.13 out of a possible total of 18 points.

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