Blog Week 21

On Monday, we continued practicing with mol problems. My group got question seven from unit five worksheet two. We got the atomic mass for iron, which was 55.8g, but since the substance was Fe2O3 we timed 55.8 x 2 = 111.6g. Then we got the atomic mass for oxygen, which was 16g, then we timed 16 x 3 = 48g because the substance was Fe2O3. After that we added those two numbers together to get 159.6 and that number is the mass for one mol. So, we then set up the equation: 2.50kg x 1000g/1kg x 1mol/159.6g, we added the 1000g/1kg because the masses need to be the same unit, so they could be canceled out. The answer we ended with was 15.7 mol Fe2O3. We then listened to the other groups questions, which were numbers six and eight. They each got the right answers, I did the same problems for extra practice, in the picture below is my work on the problems.

On Tuesday, went over how to do the problems we've been practicing in class. We first talked about turning grams to mols. First you find the molar mass of the substance in question, it relates the grams for every one mol of the substance. We then add up the molar masses of all the atoms in substance. We then came to the conclusion that the equation is: 1mol/mass(g) x g = mol. We then talked about how to turn mol into grams. First you have to find the molar mass and add up all the atoms. We the decided that the equation is: mol x mass(g)/1mol = g. Then we went onto say the equation for mol to molecules is: mol x 6.02x10^23molecules/1mol = molecules. So to get molecules to mol the equation is: molecules x 1mol/6.02x10^23molecules = mol. At the end of class we were introduced to the electrolysis apparatus.
On Wednesday, we had a shortened period, sadly to say goodbye to Mr. Toby. During the class we did an experiment, creating hydrogen and oxygen gases by adding electricity to the system. The information we wanted to obtain was the volumes of each gas, along with mass, molar masses, and mols. I got the measurements and wrote them down, but I wasn't if they were correct. On Thursday, I fixed and my work and my group ended up being correct. The volume of hydrogen was 2 and the volume for oxygen was 1. From their used the densities I looked up on Wednesday, but we had to convert them, because they were in liters not milliliters. We then wanted to find the mass. So for hydrogen this was our equation: m/2 = 89.88, m = 0.1798g. Then equation for oxygen's mass was: m/1 = 1.429g. Then we needed to find the mols. So we had the molar masses, which are the atomic masses and since it was H2 and O2, we multiplied the molar masses by two. So, hydrogen's molar mass was 2.02 and oxygen's molar mass was 32g. To get mols we set up the equations for oxygen and hydrogen. Oxygen's equation was: 1/32 x 1,429 = .0447 mol. Hydrogen's equation was: 1/2.02 x 89.99 = .089mol. Which proved that water was H2O a 2 to 1 ratio. You called it the empirical formula. You said based on the mass we can find mol, then find the ratio and then the formula. (I hope I all the numbers are right, you told us we needed to divide by a 1000 instead of multiply by 1000, so I hope I fixed it right.) This picture below shows my groups data. The one on the right is the set up of the experiment.

On Friday, we took an assessment. I didn't really like taking it on my phone. I guess I'm old fashioned in my test taking. I prefer to do my tests on paper. I think I did ok on the assessment, but some questions were really confusing.