Molar Volume of a Gas Lab

Today in class we worked on the Molar Volume of a Gas Lab. The goal of this lab is to measure the molar volume of Hydrogen gas at STP.

First, we measured out 10 mL of Hydrochloric Acid and poured it into the eudiometer.
Then, we filled up the rest of the eudiometer with water.
Next, we took a small strip of Magnesium and shaped it into a little ball and wrapped the Copper wire around it, which was placed in the stopper.
After, we put in the stopper and placed the eudiometer upside down in the stand, somewhat in a beaker half full of water.

The eudiometer's contents started to bubble, which is the evidence of the chemical reaction, and created the gas. The volume of the eudiometer minus the volume of the liquid left in the eudiometer equals the volume of the gas created by the chemical reaction.

In order to find the mass of the Magnesium strip, you have to use dimensional analysis to convert the length of the strip to grams using the conversion of 10 cm of Mg = 0.1407 grams.

The barometric pressure is 30.04 in Hg (inches Mercury), which you have to convert to millimeters.

Your water vapor pressure depends on whatever temperature you got.

Don't forget to use Dalton's Law of P(total) = P(H20) + P(H2), so that you can find the pressure of the Hydrogen gas to then find the molar volume. The total pressure is the barometric pressure, and the water pressure is your water vapor pressure.

The next scribe is Yada Thia.

Covalent Bonds

Important Things to Note About Covalent Compounds/Bonds
-Both the first and second elements of the compound are non-metals.
-The second element's name ends with the suffix -ide.
-When naming these compounds, we use Greek prefixes to determine how many atoms of an element are included in the covalent compound. ie. Dinitrogen (2) Pentoxide (5)
-The name of the first element can have any of the different prefixes except for mono-(one).
-The name of the second element can have any of the different prefixes.

Ionic vs. Covalent

-Ionic compounds consist of one metal element and one non-metal element, but covalent compounds consist of two non-metal elements. 

-The elements in an ionic compound must neutralize their charges, but elements in a covalent compound don't need to.

-Elements in ionic compounds don't use prefixes to determine the amount of atoms per element that are in the compound, but elements in covalent compounds use prefixes for their compound names. 

Prefixes for the Compound Names

Examples

-Sulfur Pentoxide - The formula would be SO5. The first element is S because we know that sulfur's atomic letter is S. The second element is O5 because we know that oxide is oxygen, and oxygen's atomic letter is O. Then since it has the prefix pent(a)-, we know that there's 5 oxygen atoms so you would put 5 as the subscript.

-Tetraphosphorus Trioxide - The formula would be P4O3. The first element is P4 because we know that phosphorus's atomic letter is P, then it's subscript is 4 because we know that there's 4 phosphorus atoms because of the prefix tetra-. The second element is O3 because we know that oxygen's atomic letter is O, then it's subscript is 3 because we know that there's 3 oxygen atoms because of its prefix tri-.

-You can find other examples in your notes from class.

Homework
-Covalent Compounds/Bonds Naming Practice worksheet
-Memorize the 8 polyatomic ions for Monday
-Study for the quiz on Monday

The next scribe will be Courtney S.