Daily recaps, assignments, and handouts will be published to the Google Classroom page. This site will no longer be updated regularly. Students were given their Google Classroom code in class to access the page.
Welcome to a new year of chemistry! This year we will be working together, doing the work of real scientists, to develop explanations to what we observe in the world around us, as well as find solutions to real world problems. Today the students were given the class policies and procedures, which entails their first homework assignment.
HW: Sign (and have a parent/guardian sign) and return the last page of the classroom policies page according to the HW policy. Today in class the students received their final exam study guide and began working on it to prepare for the exam. The exam itself will be cumulative, covering material from the entire year, and will also be open notes. The study guide itself will also be permitted to use on the exam, so students are encouraged to work through it completely and to double check all of their answers.
HW:
Today in class the students practiced using the scaling fractions method to solve problems related to all 4 of the gas laws (Boyle's, Avogadro's, Charles', and Gay-Lussac's) in order to calculate the change to temperature, pressure, volume, or amount of gas when another change is known.
Today in class we discussed the remaining Gas Laws (Avogadro's, Charles', and Gay-Lussac's). We observed these phenomena in action through a series of demos using air pumps, balloons, and lastly used a fire piston to start a fire using nothing but air..
Today in class we went over the relationship between pressure and volumes for gases. We used models to explain why the pressure of a system must increase if the volume is decreased, or conversely, why the pressure must decreased if the volume increases. This relationship we defined as Boyle's Law.
After establishing the relationship, we practiced using a scaling fraction to calculate the actual change in pressure if we know the change in volume or the actual change in volume if we know the change in pressure. To wrap up class, we finally talked about the relationship between the number of air particles a container has and its volume. We established that if the number of air particles is increasing, then the volume must also increase. Today in class we used models to visualize the changes that occur in a gas system as the size of the container changes. To do this, we sealed mini marshmallows into a syringe and sealed the tip. As we pressed in the plunger, we observed the effects it had on the marshmallows inside. Using our particle models, we worked to devise an explanation for our observations.
Today in class we discussed the effects that intermolecular forces have on the freezing point of a liquid and used this phenomenon to explain why water freezes at home in our freezers, but alcohol does not.
Today in class we discussed the difference between boiling and evaporation, and discuss what must happen for both to occur. We also saw the effects that air pressure can have on the temperature at which a substance boils by using a syringe to boil water that was not heated up to its normal boiling point.
Today in class we discussed the concept of air & atmospheric pressure and its causes. Tomorrow we will begin taking a look at the different factors that can influence air pressure such as temperatue, volume, and the number of gas particles.
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Mr. SasséGeneral Chemistry Archives
February 2016
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