Chem 1010- Chapter 5 book questions

Which of the following options correctly describe the water cycle? Select all that apply.

- A drop of water in the ocean could one day end up in a lake - Climate can affect the water cycle

What is the molarity of a 1.50-L solution containing 22.3 g of sodium chloride (NaCl)? The molar mass of NaCl is 58.44 g/mol.

0.254M Reason: M = Number of moles of solute/ liters of solution n= 22.3 g/ 58.44 g/mol=0.382 M= 0.382 mol/ 1.50 L= 0.254 M

The concentration of arsenic in a drinking water supply is found to be 1.4 ppm. What is the concentration in units of mg/L?

1.4 Reason: 1 ppm= 1 mg/L

approximately how much water per day is required to support the lifestyle of the average U.S. citizen, according to the U.S. Geological survey?

100 gallons

An aqueous solution has 124 g of a salt dissolved in 1000 g of solution. What is the concentration of the salt in units of %?

12.4%

Approximately how many people on the Earth lack access to clean drinking water?

2.1 billion

How much energy must be absorbed by 10 g of water to increase its temperature by 5 ∘C?

209J Reason: 4.184 J/goC x 10 g x 5 oC = 209 J

According to the USGS, how much water per day is needed by the average U.S. citizen?

390L

20.0 g of NaOH is weighed and dissolved in enough water to prepare a 0.10 M solution. What size volumetric flask would be required for this solution?

5.0 L Reason: 20.0 g NaOHx 1 mol NaOH/ 40.0 g NaOH= 0.500 mol 0.500 mol x 1L/ 0.10 mol= 5.0 L of solution

An aqueous solution is composed of 5.7 g of NaCl in 100 g of solution. What is the concentration of the solution, in units of %?

5.7%

According to the World Health Organization estimates, approximately how many infants and children die each day due to contaminated water?

>3000

Which of the following options correctly describe molecular polarity? Select all that apply.

A molecule that contains only nonpolar bonds is nonpolar. A molecule that containd polar and nonpolar covalent bonds could be polar or nonpolar. Overall molecular polarity depends on the geomerty of a molecule.

A(n) _____ solution is one in which water is the solvent.

Aqueous

What is the shape of a water molecule?

Bent

Which of the following would represent an example of a tragedy of the commons? (Select all that apply.)

Dumping waste into a public lake Overfishing a lake.

Which of the following options correctly describe electronegativity and its trends? Select all that apply.

Electronegativity increases from left to right. The element with the highest electronegativity is fluorine. The higher the electronegativity value of an element, the more strongly it attracts bonding electrons to itself.

True or false: A bond between O and H within any molecule is called a hydrogen bond.

False Reason: Correct. A hydrogen bond is a noncovalent or nonbonding attraction between a hydrogen atom and a lone pair of electrons on an O, N, or F atom in another molecule or a different part of the same molecule. A hydrogen bond cannot exist between two atoms that are already covalently bonded to each other. To participate in hydrogen bonding a hydrogen atom must be covalently bonded to N, O, or F.

True or false: A chemical company inadvertently dumps toxic waste into a local river, which pollutes the water for residents of a nearby town. However, this is not considered a tragedy of the commons since the company did not do this intentionally.

False Reason: This is still considered a tragedy of the commons since others are impacted by this action - either deliberate or accidental.

True or false: The boiling point of H2S would be higher than H2O due to stronger intermolecular forces

False Reason: Correct. H2O would have stronger intermolecular forces (H-bonding) & therefore the higher boiling point.

A water _____ is an estimate (for an individual or nation) of the amount of water required to sustain the consumption of goods and services.

Footprint

Rank the following bonds from the most to least polar, starting with the most polar bond at the top of the list.

H-F, P-O, C-O, C-H

Which of the following is the correct condensed molecular formula for water?

H2O

Which of the following molecules would exhibit hydrogen bonding? (Select all that apply.) HCl, H2Te, HF, H2S, NH3

HF, NH3

Which of the following species will be present in an aqueous solution of Na2CO3?

Na+, CO3 2-

When hydrogen is covalently bonded to ________ , oxygen, or fluorine there will be an attraction between such a hydrogen and a lone pair of electrons on one of the aforementioned atoms on an adjacent molecule or in a different part of the same molecule. This attraction is called a(n) _______ bond and it is the strongest type of intermolecular force.

Nitrogen, Hydrogen

Match each bond with the appropriate difference in electronegativity.

O-H 1.4 F-H 1.9 S-Cl 0.5 Si-F 2.2

Match each concentration term with the ratio it represents.

Percent(%)- amount of solute/ amount of solution x100 Parts per million(ppm)- mass(g) of solute/ 1x10^6g solution Parts per billion(ppb)- mass(g) of solute/ 1x10^9g solution Molarity(M)- mol solute/ L solution

In a(n) _____ bond electrons are not shared equally, but are closer to the more electronegative atom.

Polar Covalent

Which of the following options correctly describe the different sources of fresh water? Select all that apply.

Sea water can be used as a source of water. Surface water is found in lakes, streams, and rivers. Groundwater is found in aquifers.

Which of the following options correctly describe the different ways of expressing the concentration of a solution? Select all that apply.

Solutions with the same molarity contain the same number of molecule, ions, or atoms of solute. The units ppm or ppb are most commonly used for very low concentrations.

The quantity of heat energy that must be absorbed to increase the temperature of 1 gram of a substance by 1°C is called its _____.

Specific Heat

The quantity of heat energy that must be absorbed to increase the temperature of 1 gram of a substance by 1°C is called its _____.

Specific Heat Capacity

Which of the following statements correctly describe the illustration? (Select all that apply.)

The atoms involved in interaction A are farther apart that the atoms involved in interaction B. Interaction A is an example of an intermolecular force.

Which of the following statements correctly describe the process by which an ionic compound dissolves in water? Select all that apply.

The attraction between the H2O molecules and the ions is stronger than the attraction of the ions for each other. The positive ions are attracted to the partially negative O atom of the H2O. The positive and negative ions dissociate from each other.

Which of the following molecules is polar?

The greater the difference in EN the more polar the bond is. NH3 Reason: Ammonia contains relatively nonpolar bonds but is polar because it also contains a non-bonded electron pair.

δ-O <--- H δ+ Which of the following options correctly describe and interpret the illustration? (Select all that apply.)

The illustration depicts a polar covalent bond. The electrons in the O-H bond are closer to the O, giving it a partial negative charge.

The ratio of amount of solute to amount of solution is called the _____ of the solution.

concentration

if the sign δ- is used to mark an atom in a covalent bond, it means that _____. (select all the options that complete the sentence correctly.)

This atom is more electronegative. This atom has a partial negative. This atom has a higher electron density.

True or false: If a ppm is equivalent to 1 mg/L, then a ppb is 1 μg/L.

True

An estimate of the water used to produce a particular product is known as a _______.

Water Footprint

What is potable water?

Water that is safe to drink and cook with.

An _____ is a source of freshwater located underground.

aquifer

intermolecular forces

attractive forces between molecules

intramolecular forces

bonding forces that hold the atoms of a molecule together

Which of the following bodies of water is/are included in the natural water cycle? Select all that apply.

glaciers, lakes, rivers, sea ice

All _____ bonds are much weaker than _____ bonds.

hydrogen bonds; covalent Reason: Hydrogen bonds have only about one tenth of the strength of a covalent bond.

The attraction indicated by the arrow in the illustration is a(n) _____. (the picture is of two water atoms with the arrow pointing to a red dotted line)

intermolecular force

δ-

marks the atom with the higher electronegativity

δ+

marks the atom with the lower electronegativity

Tragedy of the commons

the situation in which a resource is common to all and used by many, but has no one in particular who is responsible for it. As a result, the resource may be destroyed by overuse to the detriment of all that use it.

Which of the following statements correctly define an aqueous solution? Select all that apply.

water is always the solvent in an aqueous solution An aqueous solution is a homogeneous mixture An aqueous solution can have one or more solutes