Iron & Copper Reaction Lab

This lab really tested not only our skills in chemistry, but also our skills in patience. It was time consuming but allowed us to see how quickly rust can form, although that was not the objective; the lab was designed so that we can use different conversion factors and data of varying data to analyze the chemical reaction of iron and copper. Iron Man approves! Better yet, Captain Kirk does!

He's eighty.  This is him at thirty-two:

Like a fine wine.

-George Spencer

Molar Volume Lab

This class was spent doing a lab to measure the molar volume of a gas. By filling a immersed cylinder with butane gas through the means of a lighter, we could interpret the volume of both cylinder filled and lighter emptied.

-Simon Sierra

Converting Between Volume and Moles

How Does One Convert Between Moles and Volume?

To convert between moles and mass, molar volume is utilized as the conversion factor. This introduces a new concept that is easily associated with our previous knowledge of the mole through the diagram below: 

What is Molar Volume?

At standard temperature and pressure (STP) one mole of any gas occupies the same volume. STP is found at 0 °C or 101.325 kPa, and at these levels 1 mole = 22.4 L. Therefore, 22.4 L/mole is the molar volume at STP.

With this conversion factor:

• You can convert from volume to moles
• You can convert from moles to volume 

What's the Process?

Like molar mass conversions, only one mathematical step is needed in these conversions: 

Examples 

• At STP an unknown gas is found to occupy 150 mL. How many moles of gas must there be? 

                         150 mL x 1 mole/ 22.4 Liters

                      = 6.70 milli-moles/ 1 000 

                      = 0.00670 moles  

• At STP, a sample of oxygen gas contains 11.5 moles. How many litters of oxygen gas are there?  

                      11.5 moles x 22.4 Liters/ 1 mole

                   = 258 L  

Below is a video that thoroughly goes over the process of converting moles to volume and back again:

  

-George Spencer

Converting Between Mass and Moles

How Does One Convert Between Moles and Mass?
To convert between moles and mass, molar mass is utilized as the conversion factor. Although simple it is important to that note that:

• The appropriate units are cancelled 
• The number of significant digits matches that of the least number of the given data  

What's the Process?

Only one mathematical step is needed in these conversions: 

 

Examples 

• How many moles are present in a 2.5 gram sample of Ammonium Phosphate?  
• Ammonium Phosphate = (NH3)PO4 
• (NH3)PO4 = 149 grams  

                         2.5 grams x 1 mole/ 149 grams 

                      = 0.017 moles 

• A sample of Hydrochloric acid contains 0.54 moles. How many grams of Hydrochloric Acid is this?  
• Hydrochloric Acid = HCl 
• HCL = 36.5 grams  

                        0.54 moles x 36.5 grams/ 1 mole 

                      = 20 grams

Below is a video that thoroughly goes over the process of converting moles to grams:

 

And likewise, here is one that explains how to convert from grams to moles: 

  

-Benedict Suratos

Molar Mass

What is Molar Mass? 

Molar mass is the mass (in grams) of 1 mole of a substance. 

How do you find Molar Mass? 

This number can be determined from the atomic mass given on the periodic table as shown below:

 

As you can see, there a0re four significant digits given in the atomic mass and in some instances even more. For our application and purposes, we will only use one digit past the decimal point for the atomic mass. Molar mass is expressed as g/mol, therefore the element above can be said to have a molar mass of 58.93 g/mol.  

• Hydrogen = 1.0 g/mol  
• Zinc = 65.4 g/mol 

How do you find Molar Mass of Compounds? 

To determine the molar mass of compounds, simply add the mass of all the atoms together: 

• Water (H2O) = 2(1.0) + 16.0 = 18.0 g/mol  
• Aluminum Chloride (AlCl3) = 27.0 + 3(35.0) = 133.5 g/mol  

The following video should clarify any confusions. Underneath that thick southern accent are some fine examples:

-Simon Sierra

Avogrado's Number

Avogadro's Number:

• Amedeo Avogadro proposed that the number of atoms in 12g of carbon be equal to a constant (This equals 1 mol of Carbon)
• This value is now called Avogadro's Number and forms the basis of all quantitive  chemistry
• Avogrado's Number: 6.02 x ×10
• For future conversions we can say and apply that: 1.0 Mole = 6.02 x 10 Atoms    
• Here's the fancy gentleman himself:   

 

He looks like a less refined Peter Lorre.   

- George Spencer

Hydrate Lab

On Friday, we did a lab on hydrates and it taught us how each hydrate has a specific amount of water that can be burned away and then measured.

-Ben Suratos