6.03 Calorimetry Lab Report

Introduction: Yeast (saccharomyces) is a common single-celled fungus. They are microscopic plants that exist naturally on Earth. They are known for their ability to ferment the carbohydrates in the flour and gain energy from this digestion. Some food products created by yeast include bread, beer, wine and cheese. Yeast is mistaken as lifeless, dry powder used to make bread, but, it becomes active in moist environments.

You will then pour half of the graduated cylinders contents (20ml) into each of the 2 medium beakers.

1 I measured the temperature of NaCIO solution and “solution B” (using the same thermometer; temperature of solutions were equal). Then recorded my data in the table.

Procedure: Step 1: Prepare and label 2 40 mL of water in a beaker and label one A and the other B. Step 2: Heat both beakers to the temperatures that are being tested. Step 3: Prepare 2 g of yeast for each beaker. Step 4: Prepare .25 g of sucrose for each beaker. Step 5: Once water is heated add the 2 g of yeast and .25 g of sucrose to each beaker. Step 6: Stir each one simultaneously for 1 minute.

Record all my result in a suitable table stating their initial mass, final mass, mass change and percentage mass change.

5. Add the 40cm3 of HCl to the NaOH solution, close the calorimeter with the lid (making sure that the thermometer sticks through the hole) and start the stopwatch

The goal of this lab was to make a NaCl^ solution and calculate its molarity so that students can become acquainted with “volumetric glassware, the balances and quantitative transferring of liquids.” 25 mL of NaCl solution was completely transferred with AgNO_3 solution test and the molarities of the original 25 mL and diluted 250 mL solutions were calculated.

The 0.0 M to 0.2 M sucrose solutions remained positive on the graph in figure one, while steadily approaching 0.00% mass difference. When the concentrations were 0.3 M to 0.5 M sucrose the percent mass difference became negative, decreasing continuously. As shown in Figure 1, the control 0.0 M sucrose solution yielded the highest percent mass difference (13.24%). From there, the percent difference in mass continually decreased in the treatment sucrose solutions; 0.1 M yielded a 4.76% difference, 0.2 M yielded a 2.08% difference, 0.3 M yielded a -6.56% difference, 0.4 M yielded a -15.63% difference, and 0.5 M yielded a -20% difference. Between the 0.2 M and 0.3 M treatments, the percent difference in mass became negative (the linear trendline

| Different concentrations of sucrose solution (specifically, 0.25mol/dm³, 0.5mol/dm³, 0.75mol/dm³and 1.00ml/dm³) and distilled water (0.00mol/dm³) will be used.

The molar mass, the number of moles in the sample, and the number of representative particles in the sample were also recorded.

Set up support stand with support ring and wire gauze for the purpose of heating water. Fill 400 mL beaker half way with tap water. Place it on the wire gauze over the burner. While it heats, weigh your dry test tube with a cor to 0.01g and record. Fill the test tube and metal in the beaker of water and it it boil. The Cork is used

With your thumb over the top of the test tube, shake the test tube with the yeast inside so it dissolves

To prepare experiment 1, labels were put on four separate 50 mL plastic tubes. They were each labeled, “Negative control A”, “Positive control B”, “Positive control”, and “Experimental”. Fermentation tubes were also labeled in the same way as the vials. Next, glucose in the amount of either 2% or 6% and water was extracted from beakers using a pipette pump. The water and glucose were then mixed in the plastic tubes before adding the yeast from a separate beaker, also extracted by a pipette pump. It was important to make sure that the yeast is added last, as the reaction will happen as soon as yeast and sugar come into contact. After the solutions were mixed together, they were put into their previously labeled fermentation tubes. After the

Beaker A was filled with half warm water and half ice so the temperature was at 10˚C

We will put a drop or two of oil on top of each solution to stop fungus and bacteria colonies developing on the surface. Because it was not oiled in the pre-test, bacteria from the air landed on the solution and started to multiply, feeding on the solution, in turn making the experiment inaccurate.