Acc. Chem. Blog 4

Accelerated Chemistry Blog #4

          The first major topic we covered in this unit was naming and balancing equations.  The most important thing to remember when balancing equations is charges.  Balanced equations will always have an even charge.  Positive charged ions are called cations, while negatively charged ions are anions.   There are some simple techniques to make balancing equations easier.  A good example is using fraction charges then canceling them out in the end.  On the periodic chart, in general, positive metals are found on the left while negative elements are found on the right.

          In addition to balancing equations we learned about different types of chemical reactions.  The five types of reactions we learned about are synthesis/combination, decomposition, single replacement, double replacement, and combustion.  In a synthesis reaction two elements combine into one.  During decomposition a compound breaks down into smaller compounds or elements.  During single and double replacement atoms of elements essentially swap places.  As you can probably guess by the name, combustion reactions involve a substance burning with Oxygen.  We did a lab in class that involved performing 9 experiments then determining the type of reaction and balancing the equations.  We determined the type of reaction by properties observed, splint tests, and litmus paper.

          The last major topic we covered was the Activity Series.  The activity series is the order in which elements react with one another.  At the top of the list for metals we have lithium and rubidium and some non-metals include Fluorine, Chlorine, Bromine, and Iodine.  In class we used a demo to show this concept.  By placing metals in other metals solutions you could see that some metals reacted while others didn't.

         As we reach the end of the unit I finally feel like I have a good grasp on all the material we covered.  The demos in class did a good job showing concepts and most were fun to watch too.  If we could cover one thing more I wouldn't mind talking about the Activity Series more.  I understand how it works but I feel like we rushed through it in a day.

Accel. Chem. Blog #3

Relative Mass

        Relative mass is an molecules mass compared to 1/12 of a c-12 (Carbon-12) atom.  For elements, this is applied as the atomic mass on the periodic table.  In class we did several labs to work with relative mass.  One lab involved weighing out rice, beans, and popcorn kernels.  Then we compared the masses to determine the relative mass of the popcorn and beans if rice was 1:1.  This lab was a good entry point into our understanding of relative mass.  Once we understood how to calculate relative mass we were able to start working with the relative mass of elements and moles.

Avogadro Number

         

          Avogadro's number is the number of atoms in a specific mass of a substance.  Avogadro's Number is massive.  It is expressed as 6.02X10^23. Also written as:

602,000,000,000,000,000,000,000.00

The number above is one mole.  Abbreviated mol, a mole is used to calculate mass relative to C-12

Molar Mass

        Molar mass is the mass of one mole of atoms.  An elements molar mass is also knows as it's atomic mass.   The periodic table is arranged so molar mass increase from left to right.

        

        Throughout this last part of the unit we have been performing many calculations using molar mass.   The most import thing to do when performing these calculations is to make sure you set up your rations.  Ratios are important because molar mass is based on rations to c-12.  

My Thoughts

        As this unit comes to an end I feel like I have a good grasp on the concepts we covered.  The labs we participated in were a good way to get the basics across then expand the ideas and apply them to other situations.  I feel like the more I work with molar mass calculations the more comfortable I'll become and experience is the only thing that can be improved.  There aren't any ideas that I don't understand at this point