HCC CHEM1305 2021 January Discussions Latest (Full)

CHEM1305 Introductory Chemistry

Chapter 1 Discussion

Chemistry in Our Everyday Lives

In this discussion, you will give an example of an item used in our everyday world that was made with chemistry (hint: everything man-made was made using chemistry!). List the item first and then give a brief description of the chemistry behind the item.

You can come up with your own idea, but I highly recommend using an item from the following website: https://pubs.acs.org/cen/whatstuff/stuffABCText.html (Links to an external site.)

There, you can click an item, and use the corresponding article to come up with a description of the chemistry behind that item.

Your post must be at least 3-4 sentences in length.

Click "Reply " below this box to post to the discussion.

To help, here is an example discussion post:

Dryer sheets

Dryer sheets are pieces of material covered with a special softening agent. The softening agent will melt off when heated and next stick to the fabrics as they are being dried. The softening agent not only makes fabric feel softer, it also helps to dissipate static charge. A heat-resistant fragrance is often added to dryer sheets, which will transfer to fabrics as well.

 

CHEM1305 Introductory Chemistry

Chapter 2 Discussion

Metric or English System?

In this discussion, you will give your opinion about which system of measurements you prefer. In the United States, the English system is used (units of length are inches, feet, yards, miles; units of mass are ounces and pounds; units of volume are quarts, pints, gallons; units of temperature are degrees Fahrenheit). In the rest of the world, the Metric system is used (units of length are centimeters, meters, kilometers; units of mass are grams and kilograms; units of volume are milliliters and liters; units of temperature are degrees Celsius).You should first state either "English" or "Metric" to say which you prefer. And next add 1-2 sentences to explain why.

 

CHEM1305 Introductory Chemistry

Chapter 3 Discussion

Classification of Matter

Think of a substance that you may see everyday. State whether it is an element, a compound, a homogeneous mixture, or a heterogeneous mixture and use 1-2 sentences to describe why. I recommend a web search to help you (example search: "is salad dressing an element, compound, homogeneous mixture, or heterogeneous mixture").

CHEM1305 Introductory Chemistry

Chapter 4 Discussion

Building Isotopes

This discussion is more of an activity. Please click on the following link (Links to an external site.) to visit the Isotopes and Atomic Mass simulator.

Click on the simulator, and choose the 'Isotopes' option

Once there, choose one of the elements seen in the top right corner (only the first 10 elements are available)

Expand the 'Abundance in Nature' box on the right

Determine which isotopes of the element are stable by adding or taking away neutrons from the nucleus (a bucket of neutrons is to the left)

Report which isotopes are stable (using the correct isotope name) and what percent abundance of each isotope is found in nature

I have used hydrogen as an example to show how you should report your findings:

Hydrogen-1 has 99.9885% natural abundance

Hydrogen-2 has 0.0115% natural abundance

All other isotopes are NOT stable

I have included screenshots of the hydrogen example below. You DO NOT need to upload any screenshots, I have only put them here to help guide you.

H-1

H-2

H-3

If the images do not appear, see them in the .pdf file here

 

CHEM1305 Introductory Chemistry

Chapter 5 Discussion

What is Your Favorite Element?

In this discussion, you will tell us about the element that you find the most interesting.

You should visit the photographic periodic table (http://periodictable.com/ (Links to an external site.)), which has photographs of all the stable elements as well as facts and stories about each element. Choose the one that looks the most interesting to you and click on it to read about it. To contribute to this discussion, first name the element you chose and next copy one (or more!) of the facts or stories and post it here.

Here is an example:

Element: Radium

Radium was once widely used in self-luminous clock and watch hands, until too many watch factory workers had died. It had not been understood yet that exposure to radium leads to radiation poisoning and eventually death. Those antique watches are still quite radioactive, and will stay that way for thousands of years.

 

CHEM1305 Introductory Chemistry

Chapter 6 Discussion

Uses of Inorganic Compounds

1616 unread replies.3535 replies.

In this discussion, you will choose one of the inorganic compounds from the table below. First, state whether it is a binary ionic compound, ternary ionic compound, binary molecular compound, binary acid, or ternary oxyacid.

Next, do a web search to see what uses the compound has. Use the term "what are the uses of [compound]" and list at least two of the uses you find.

For example aluminum hydroxide is a ternary ionic compound. And a search of the term "what are the uses of aluminum hydroxide" shows that it is used both as an antacid and to reduce phosphate levels in people with certain kidney conditions.

Al(OH)3, aluminum hydroxide

BaSO4, barium sulfate

CaCO3 calcium carbonate

CCl4, carbon tetrachloride

CF4, carbon tetrafluoride

CO2, carbon dioxide

ClO2, chloride dioxide

HCl(aq), hydrochloric acid

HClO4(aq), perchloric acid

HF(aq), hydrofluoric acid

H2O, dihydrogen oxide

H2SO4(aq), sulfuric acid

KI, potassium iodide

K3PO4, potassium phosphate

Mg(OH)2, magnesium hydroxide

MgSO4, magnesium sulfate

Na2CO3, sodium carbonate

NaCl, sodium chloride

NaF, sodium fluoride

NaHCO3, sodium bicarbonate

Na2HPO4, sodium hydrogen phosphate

NaOCl, sodium hypochlorite

NaOH, sodium hydroxide

Na2SO3, sodium sulfite

NH3, nitrogen trihydride

(NH4)2CO3, ammonium carbonate

NH4NO3, ammonium nitrate

NO, nitrogen monoxide

NO2, nitrogen dioxide

P4S2, tetraphosphorus disulfide

SF6, sulfur hexafluoride

SO2, sulfur dioxide

SiH4, silicon tetrahydride

TiO2, titanium(II) oxide

ZnO, zinc oxide

 

CHEM1305 Introductory Chemistry

Chapter 7 Discussion

Chemical Reactions in Daily Life

In this discussion, you will do a web search to find an example of a chemical reaction which may be encountered in daily life. Describe a little about the chemical changes that occur. If possible, classify the chemical reaction and write out the chemical equation.

See each of these websites for some ideas:

https://sciencestruck.com/chemical-reactions-in-everyday-life (Links to an external site.)

https://www.thoughtco.com/chemical-change-examples-608334 (Links to an external site.)

For example, baking soda (sodium hydrogen carbonate) is used in baking. When the baking soda heats up, carbon dioxide and water vapor gases are released, leading to the cookie dough or cake batter rising. This is a decomposition reaction, and the chemical equation is:  2 NaHCO3(s) heatrxn Na2CO3(s)  +  H2O(g)  +  CO2(g)

 

CHEM1305 Introductory Chemistry

Chapter 8 Discussion

How Big is Avogadro's Number?

In this discussion, you will do a calculation using Avogadro's number, 6.02 × 1023, or 1 mole. Think of an everyday item and either do a google search to see what it's mass is or else measure it's mass yourself. Next, multiply that mass by Avogadro's number to determine how much 1 mole of that item would weigh. Report your result in both scientific notation and as an ordinary number.

For example, 1 m&m candy weighs about 0.88 g

0.88 g × 6.02 × 1023 = 5.3 × 1023 g = 530,000,000,000,000,000,000,000 g

 1 m&m = 0.88 g

1 mole m&m = 5.3 × 1023 g    or    530,000,000,000,000,000,000,000 g

 

CHEM1305 Introductory Chemistry

Chapter 9 Discussion

Limiting Reactants

This discussion is an activity. Please click on the following link (Links to an external site.) to visit the Reactants, Products and Leftovers simulator.

Click on the simulator, and take some time to practice the limiting reactant concept first with the 'Sandwiches' option and next the 'Molecules' option

When you feel you have had enough practice, choose the 'Game' option

Practice with the 'Level 1' game (you will see in each game, you have a few attempts to get the right answer)

Next, choose the 'Level 2' game

Once there, you will choose one of the 5 challenges within the game to report on

For the challenge you pick, you must report:

the balanced chemical equation

number of molecules of the reactants for your example

number of molecules of the products for your example

number of molecules of the leftovers for your example

 Here is an example to show how you should report your findings:

1 H2  +  1 F2  →  2 HF

5 H2  and  4 F2

8 HF

1 H2  and  0 F2

 I have included screenshots of the example below. You DO NOT need to upload any screenshots, I have only put them here to help guide you.

10_1.png

10_2.png

10_3.png

10_5.png

 

CHEM1305 Introductory Chemistry

Chapter 10 Discussion

Scuba Diving

A scuba diver is at an underwater depth where the surrounding pressure is 3 atm. The diver must be very careful when coming up to sea level, where surrounding pressure becomes 1 atm. The reason has to do with the volume of gas in the diver's lungs and gas bubbles that exist in the blood vessels and other tissues.

Using Boyle's Law, discuss why this is.

 

CHEM1305 Introductory Chemistry

Chapter 11 Discussion

Properties of Liquids and Solids

For this discussion, you will choose one liquid AND one solid from the table below. For the liquid, you must state what type(s) of intermolecular forces exist between molecules of that liquid. For the solid, you must state what type of solid it is (either ionic, metallic, covalent network, or molecular).

Liquids                                                  Solids

water, H2O                                         sodium chloride, NaCl

ethanol, C2H5OH                             diamond, C

bromine, Br2                                      copper, Cu

ether, C2H5OC2H5                          sulfur, S8

chloroform, CHCl3                           aluminum, Al

acetone, CH3COCH3                       calcium carbonate, CaCO3

pentane, C5H12                                                iron, Fe

butanol, C4H9OH                             zinc oxide, ZnO

 

CHEM1305 Introductory Chemistry

Chapter 12 Discussion

Molecule Shapes

Visit the following website: https://phet.colorado.edu/en/simulation/molecule-shapes (Links to an external site.)

Click on the "Molecule Shapes" simulation, and next choose the "Real Molecules" option.

Choose a molecule from the top right corner. Please choose either CO2, SO2, BF3, NH3, or CH4, as the other options involve geometries that will not be discussed in this course. Try clicking on the molecule and dragging it around to get a feeling for the 3-dimensional structure.

Once you have made your final selection, click the boxes at the bottom to name the 'Molecule Geometry' and 'Electron Geometry' and report your findings. The molecule H2O is used below as an example.

Molecule: H2O

Molecule Geometry: Bent

Electron Geometry: Tetrahedral

(a screenshot of the simulation is given below, you do not need to include the screenshot in your answer)