SG Chem Reflection week 4

Throughout the process of studying unit 5,  I have definently continued to struggle with the chemical equations and setting them up correctly.  Thankfully, as the week progressed and the amount of practice worksheets we have received have helped immensely.  By the time the bell rang on Friday, I had a confident understanding of how to find the amount of atoms and moles in a substance.  In addition, I also realized how to set up the chemical equations for each problem and how they are similar.  I am also able to easily figure out the information and specific numbers needed to complete the problems to calculate the correct answers.  

In my opinion, my favorite worksheet we did was the Unit 5 Worksheet 2 with sample containers.  This is the worksheet we completed on Friday and every group had to do a different problem and present their thoughts in front of the class.  When I was first given our problem, I couldn't remember how to start it.  After a few groups presented incorrectly, we were shown how we were doing the problems wrong and what we need to do to fix them.  At this time, there was about three more groups that had to present and once they set up their chemical equations and information correctly, it became very simple how to complete each of theses problems and find the correct answer.  Here are a few examples of how to set up the problems correctly.

This is an example of a problem when you are asked the find the amount of atoms.  We know this because you are using the chemical conversion of 6.02*10^23 over 1 mole.  If you just wanted to find the moles of the problem, you would not need to multiply the chemical equation by the last ratio which is 6.02*10^23 over 1 mole. 

In this problem, we are being asked how many hydrogen moles are in the problem.  We are able to notice this because there is 8 moles of hydrogen over 1 mole because we have 8 hydrogens in the chemical compound.  In my opinion, this concept is slightly harder to remember how to do it because we do not practice is as much as we do finding the moles and atoms.  

A simple way to study this concept is by making a check list of things to do for each predicament.  

Finding Moles:

1. Find the mass and do the mass(g)*(times) and a line.  

2.  Put the same units you used for the mass on the bottom of the line and write 1 mole of the chemical compound on top of the line.  We do this because we are good chemistry students who keep track of their units. 

3.  Due to the fact we will have a chemical compound of some sort, we have to find the atomic number and add them together.  The example we will use for the chemical compound is NaO3.  Because we have 3 oxygen atoms, we have to multiply the atomic number of oxygen by 3.  

4.  Now you may be wondering why we have to find this number and how the final chemical equation will look.  Using the example of 4.123 of the mass, this is how the final chemical equation finding the amount of moles will look.  You will notice the units cancel out because I am a good chemistry student. Therefore, this is how we calculate the amount of moles in a specific chemical compound with a specific mass. 

Finding Atoms:

1.  We are going to use the same mass and chemical compound in the checklist for finding moles. There is only one step we have to add when finding atoms.  But first, we need the information from the previous equation. Due to the fact we need the amount of moles to find the amount of atoms, this is the information needed from the previous equation.

2.  Now we use the moles we found in equation one to set up a new ratio.  When you are finding atoms, we always use 6.02*10^23 over "x" moles.  The "x" moles is the moles we found the the previous equation which in this case is 0.581 moles.  This is how the next equation would be set up below.

3.  To finally solve the problem for atoms, we would plug into the calculator 4.123* 6.02*10^23/70.99/0.581.  Because I am a good chemistry student, I cancel my units out and left with atomsNaO3. 

Finding the amount of moles of a specific element:

1. Going off of the problems above, we are going to be solving the amount of oxygen moles in the problem.  To do this, we need two pieces of information from the equations used to find the amount of moles.  We need the mass and the amount of grams all the elements added together equal. 

2.  With information, we are going to add another conversion ratio.  Due to the fact, we are finding the amount of oxygen and we have three atoms in the compound, we use the ratio 3 mole of O divided by 1 mole. 

3.  You finish the problem by plugging this into the calculator: 4.123*1*3/70.99/1=.1742 moles of oxygen in the problem. 

With this information and step by step explanations and examples, it make solving theses problems much easier.  When you use the chemical equations and conversions, it makes finding the correct solutions easier to understand.  In addition, it helps set up the equations for future problems.