Deicer Magnesium Chloride

The purpose of this experiment was to determine the heat of combustion of magnesium using Hess’s Law. This experiment was significant in understanding how heat can be absorbed or released and how using a calorimeter can help measure heat flow. Part A of this experiment used two dry Styrofoam cups and a magnetic stir bar to create a calorimeter. Temperature was measured and distilled water was placed into the calorimeter, and after 2-3 minutes, boiling water was mixed in. The computer continued to take data for 6 minutes and then the calorimeter was reweighed and emptied. Part B and C were the same, only using two different types of magnesium (magnesium ribbon (part B) and magnesium oxide (part c)) instead of the boiling water. The major result is that all of these experiments release energy because the calorimeter temperature increased.

The purpose of this experiment was to determine the percent by mass in a hydrated salt, as well as to learn to handle laboratory apparatus without touching it. The hydrated salt, calcium carbonate, was heated with high temperature to release water molecules. Gravimetric analysis was used in this experiment to determine the percent by mass of water in a hydrated salt. The hypothesis of this experiment was accepted on the basis that the percent by mass of volatile water in the hydrated salt would be fewer than 30%. The percent by mass was determined by the mass of water loss devised by the mass of hydrated salt multiplied by total capacity

The aim of the lab was to determine the molar enthalpy of the combustion of magnesium using values from reactions between magnesium and magnesium oxide in hydrochloric acid solution using Hess’s Law and Calorimetry. The calculated molar enthalpy of the combustion of magnesium from this experiment was -633.6KJ/mol. This result was found by putting a known mass of magnesium metal as well as magnesium oxide powder into a concentration of HCl. Firstly, a styrofoam calorimeter was used to determine the standard reaction temperature of magnesium metal and hydrochloric acid. Next, calorimetry was again used to determine the reaction temperature of magnesium oxide and hydrochloric acid. Lastly, the thermochemical equations for the two

    In this lab, a calorimeter was used to find the enthalpy of reaction for two reactions, the first was between magnesium and 1 molar hydrochloric acid, and the second was between magnesium oxide and 1 molar hydrochloric acid. After the enthalpy for both of these were found, Hess’ law was used to find the molar enthalpy of combustion of magnesium, using the enthalpies for the two previous reactions and the enthalpy of formation for water. The enthalpy of reaction for the magnesium + hydrochloric acid reaction was found to be -812.76 kJ. The enthalpy of reaction for the magnesium oxide + hydrochloric acid reaction was found to be -111.06 kJ. These two enthalpies and the enthalpy of formation for water were manipulated and added together using Hess’s law to get the molar enthalpy of combustion of magnesium. It was found that the molar enthalpy of combustion of magnesium was -987.5 kJ/mol. The accepted enthalpy was -601.6 kJ/mol, which means that there is a percent difference of 64%. This percent difference is very high which indicates that this type of experiment is very inefficient for finding the molar enthalpy of combustion of magnesium. Most likely, a there are many errors in this simple calorimeter experiment that make it inefficient for finding the molar enthalpy of combustion of magnesium.

Because it is dangerous to burn magnesium, it is not possible to directly record heat change. Our lab team suggests an indirect way of determining the heat of combustion for magnesium. To accomplish this, we need to perform two separate trials. One uses a solid (powder) version of MgO, while the other uses Mg ribbon. With the results from these, we can use Hess’ Law to determine q=∆H. This provides both a safe and successful way of indirectly determining the heat of combustion for magnesium.

In order to fulfil the labs purpose, the lab was split into two parts. The first part consisted of measuring and determining the freezing point depression of the solution water. The second part consisted of measuring and determining the freezing point depression of a solution that consisted of water and an unknown solute.

The purpose of this experiment was to find the amount and percent of water in a hydrated salt. Hydrated salt contains water molecules chemically bound to it while anhydrous salt is a substance that fire can readily remove the water molecules. Using the gravimetric analysis method, the sample salt was measured, heated, and was measured again after cooled down to room temperature; this procedure allowed the weight of water lost in the salt to be obtained. After two trials, the water in the salt was determined to have an average percent water of -35.04%. The null hypothesis, the heat will not affect the amount of water lost, was rejected ,however, the alternative hypothesis, the heat will allow for there to be water lost, was not supported.

It is to tell how the reaction between magnesium and hydrochloric acid will be effected if we change the concentration of hydrochloric acid.

Therefore, qmetal = -qwater. The mass of the sample was recorded from the baggie. The temperature change

125.84 / (1 - 0.3641) = 197.9 g/mol = 197.9 - 125.8 = 71.16 g = 71.16 g (1 mol / 18.01 g H2O) = 3.95 = = MnCl2 .

In the lab before spring break, we had to calculate the percent composition of water in 1 of the hydrated salts. We then weighed in mass for the empty test tube, put the Magnesium Sulfate in the test tube, and measured it before heating. After using a bunsen burner to take the water out of our magnesium sulfate. Following the heating, we let it cooled, and then weighed in mass. My hypothesis is that Magnesium Sulfate would lose the most amount of water because it had the most amount of water while remaining the lightest. Even though my hypothesis wasn’t the greatest explanation, I still ended up being correct that the magnesium sulfate lost the most amount of water (different of before minus after heated).

How does the mass of ice affect the temperature of the final temperature of the iced latte? (17)

Figure 16. Solution heated contained 50.0676 g of ethanol and 42.09 g of water which, was then heated.

Throughout this experiment freezing point of water will be mentioned continuously so what is the freezing point exactly? The freezing point is the transition of when water turns to ice this happens at a certain temperature 32 degrees Fahrenheit or 0 degrees Celsius. “The typical freezing point of fresh water is 0° Celsius [32° Fahrenheit]. Generally, water molecules are composed of hydrogen and water molecules and they have bonded together into a crystalline structure ice.” (http://www.worldofchemicals.com/558/chemistry-articles/how-does-salt- lower- the-freezing-point-of-water.html, Data Research Analysis, 2017) This shows that when water turns to ice its a change in matter caused by the temperature. Which leads to why it can be altered because the temperature can always change and fluctuate. When a substance is added it can really take a toll on how the freezing point takes place. “While pure water freezes at 0°C (32°F), salt water needs to be colder before it freezes and so it usually takes longer to freeze. The more salt in the water, the lower the freezing point. Very salty water freezes at around -21 °C, or

The scientist's hypothesis is if there is more solute added to the water, then the water’s freezing point will decrease based on the number of grams of solute. To test the hypothesis the scientists will constantly add more salt/sugar to the water to see how much freezing point decreases per gram.