Chemistry | Chemistry homework help

When 500.0 mL of 0.10 M NaOH solution (containing Na+ and OH- ions) is mixed

with 500.0 mL of 0.10 M Mg(NO3)2 solution (containing Mg2+ and NO3- ions) a

precipitate of solid Mg(OH)2 forms, and the resulting aqueous solution has pH =

9.43. Based on this information, determine the value of Ksp for Mg(OH)2. Show

your reasoning clearly.

Problem 2

0.30 moles of HOCl are added to sufficient water to make 1.0 L of solution at 25 °C. Finish the table

The Ka of HOCl, at 25 °C, is 2.9 × 10–8, determine x.

Problem 3

A certain gaseous hydrocarbon is found to be 88.8% C and 11.2% H by mass. The

compound has a density of 2.12 g/L at 31 °C and 742 torr. a) What is the empirical

formula of the compound? b) What is the molecular weight of the compound? c)

What is the molecular formula of the compound? d) Draw a possible structural

formula for the compound.

Problem 4

Salicylic acid (shown below) is a weak acid with Ka = 3.0 × 10–4.

a) Complete the following reaction of salicylic acid with water.

b) Calculate the pH of 50 mL of 0.15 M salicylic acid.

Problem 5

a) Write a chemical equation that describes the dissolution of solid AuCl3 to Au3+

and Cl– ions found in water. b) Write the expression for the Ksp of AuCl3. c)

Calculate how many grams of Au3+ would be found in one liter of a saturated

solution of AuCl3. The Ksp for AuCl3 is 3.2 × 10–23.

Problem 6

Assume that you dissolve 10.0 g of a mixture of NaOH and in 250.0 mL of water and titrate with 1.50 M

hydrochloric acid. The titration is complete after 108.9 mL of the acid has been added. What is the mass

in grams of each substance in the mixture?

113) Chemistry Lab 11$

Lab 10
Concept Map of Chemistry 121 Major Topics

Overview: You probably noticed that our current unit does not contain a “Lecture Notes” tab with a concept map.  That is because you will be creating your own concept map of key Chemistry 121 topics as your final lab activity!  You may look back at the concept maps contained under previous “Lecture Notes” tabs for ideas.  Your map should fit on one computer-generated page, and only needs to contain main ideas.  Think of this activity as an alternative to writing a course outline, or a course summary.

Lab 10 Expectations

For up to 25 points, you will develop a comprehensive, computer-generated concept map of the main ideas covered in Chemistry 121.  This map should resemble the maps that I include in the “lecture notes” section of each of our units, and should feature what you believe are the most important details in our course! 

Maps need to be submitted to the Lab 10 dropbox by December 16th. Please make sure your map is saved as a .jpg file – I often cannot open other people’s .cmap files on my computer!  Questions?  Just ask!

Concept Mapping Resources

Directions:  Everyone should visit the first link to gain a general understanding of what concept mapping is, how to create a concept map, and the reasons for creating and using concept maps.  Then, everyone will need to download concept mapping software to use for this assignment.  Two options are provided below (you only need to download one form on concept mapping software, not both!).  Link 2 will direct you to free software.  Link 3 will direct you to a free 30 day trial of a different software package.  Please investigate both Link 2 and Link 3 before making your decision about which software to download!  Questions?  Just ask!

1.  The following website provides a clear explanation of how to develop a concept map.  In addition, this website shows you several examples of concept maps.  Finally, the website contains links to other websites that you may want to investigate:

http://www.graphic.org/concept.html

2.  Free Concept Mapping Software Link!  This is the software that I use to create our “lecture notes” maps.  When you visit the following site, click on Downloaded and follow the instructions that appear.  Pros and Cons:  Some people say that this software is not as easy to use or as fancy as Inspiration concept mapping software.  However, it is absolutely free – you may download it for free, with no time limit on its use!

http://cmap.ihmc.us/

3. Free 30 Day Trial of Inspiration software!  When you visit the following site, simply follow the given directions.  Pros and Cons:  Inspiration is powerful software, and is easy to use.  If you like to use graphics, you may prefer Inspiration over the cMap program (above) that I use.  Because it is so popular for concept mapping, Inspiration can only be used free for 30 days.  After 30 days, if you wish to continue using the software, you will need to pay a fee.

http://www.inspiration.com/

(IN THE FOLLOWING PAGES YOU WILL FIND EXAMPLES OF THE INDIVIDUAL CONCEPT MAPS THAT WERE PROVIDED FOR EACH UNIT)

 UNIT 1: PROPERTIES OF MATTER: ATOMIC AND MOLECULAR STRUCTURE

 UNIT 2: ELEMENTS AND COMPOUNDS: ATOMIC AND MOLECULAR MASSES

 UNIT 3: THE PERIODIC TABLE OF ELEMENTS

 UNIT 4: BONDING: IONIC AND COVALENT COMPOUNDS: VSEPR THEORY

 UNIT 5: PROPERTIES AND BEHAVIORS OF GASES (There is no example for this unit but below were the key concepts learned in this unit).

 UNIT 6: CHEMICAL THERMODYNAMICS

 UNIT 7: CHEMICAL REACTIONS

 UNIT 8: