Unknown Metals Using Calorimetry

The purpose of this lab is to figure out the mass percentage of copper in a penny. Furthermore, by doing this lab we will practice using a spectrophotometer and review the names of equipment such as volumetric glassware, pipets, and volumetric flasks.

In order to measure the heats of reactions, add the reactants into the calorimeter and measure the difference between the initial and final temperature. The temperature difference helps us calculate the heat released or absorbed by the reaction. The equation for calorimetry is q=mc(ΔT). ΔT is the temperature change, m is the mass, c is the specific heat capacity of the solution, and q is the heat transfer. Given that the experiment is operated under constant pressure in the lab, the temperature change is due to the enthalpy of the reaction, therefore the heat of the reaction can be calculated.

For q, you found how much heat was gained by the water so you know that same amount of heat was lost by the metal. Therefore, qmetal = -qwater. The mass of the sample was recorded from the baggie. The temperature change

Weight 30 dry pre-82 pennies which get 89.77g, using 30ml initial volume measuring the volume of 30 pennies, record the data 10.0ml. Using equation Density= Mass/Volume, get the density of the pre-82 pennies is 8.98g/ml. Then calculate the error%=0.10%, and the deviation%=1.29%.

The first part of this lab’s objective was to find the calorimeter constant using DI water. We accomplished this by first checking the temperature and then adding 20 mL of cold DI water into our calorimeter. Next we collected 20 more mL of DI water in a 50 mL beaker and placed it onto a burner in order to heat it. We removed the beaker once the temperature of the water reached 60º celsius. After we removed the water, we poured it into the calorimeter with the cold water and took the temperature. The temperature ended up being 37º celsius. From this information we were able to calculate for qhot, qcold, qcal and Ccal. To be as accurate as possible we conducted this same test three more times and used the averages from all Ccal calculations as the final Ccal.

Are pennies better clean or dirty? Clean, of course. Clean pennies are probably used more than dirty pennies, but maybe just clean all the dirty pennies with the products: orange juice, coca cola, and taco sauce and see which one cleans the pennies the best, so then just use those. If any of these products cleans pennies, then coca cola will clean the pennies the best. For independent variable it was the products and the dependent variable is the clean pennies. The control group is the coca cola and the experimental group is orange juice, coca cola, and the taco sauce. For this experiment there was only a few steps to do in order to have clean pennies. After all the materials are ready then pour the products into cups and put at least two pennies in each product. Once the products are in the cups then set timer for 30 minutes and repeat this step for three trials. Collect the weight of the pennies after 30 minutes each time and write it down to see which of the products took off most of the dirt on the penny. Collect all the other data that is needed. This is just one way that cleans pennies but

1. 100 + 273 K = 373 K 150 + 273 K = 423 K 960 L x 423 K / 373 K = 1,089 L 2.

Use approximately 2 feet of aluminum foil to wrap around the burner stand and beaker to minimize heat loss.

To prepare a quantitative solution, you need to know the weight of the substance and the quantity of the solution. For example, you have 40 grams of NaOH (Sodium Oxide) in 1000mL of water. The amount of water and weight of the substance makes a Mole. one mole is equal to 1000mL of water and 40 grams of NaOH and varies by the amount of water you have but the weight of the substance must also change. To make a correct solution, you need to know the atomic mass of the substance and how much water you have in mL or L. If there are multiple elements, you need to add the combined weight of all elements (EX. NaOH= 23+16+1+40 grams.) and then divide the weight by the mass. To make a solution, you should use a beaker or flask that can measure at least

The purpose of Step 8 is to make sure we get the exact mass of the solution. There could be trapped molecules of water in the solution. Heating the solution would evaporate the water molecules.

In the lab Which Is Your Metal, we attempted to identify an unknown metal by determining its specific heat capacity. We began by choosing a sample of metal, finding its mass, and describing it. We found the temperature of our boiling water. Then, we calculated the volume and temperature of the water in our calorimeter before and after the experiment. Through these calculations, we determined that the heat transferred to the calorimeter water from the hot metal was 595.65J (6.0x10²J with proper significant figures). After finding the heat transferred, we were able to calculate the specific heat capacity and match it to the correct metal. Our specific heat capacity came to 0.26J/g°C, which was closest to the

Throughout the documentary, Lourdes fights to clean up the 6,000 tons of lead slag at the abandoned factory, Metales y Derivados (De La Torre & Funari, 2006, 27:02). When the factory was shut down, toxic chemicals “like sulfuric acid, cadmium, plastic, and lead” (De La Torre & Funari, 2006, 27:52) were left exposed to the elements and the surrounding community. To clean Metales y Derivados, it would take millions of dollars—money that the promotoras and Mexican government does not have (De La Torre & Funari, 2006, 29:30). Lourdes’s effort does pay off to some extent: once international media picked up the story, the Mexican government and the US Environmental Protection Agency provided her environmental justice group with US$65,000 to begin

The element I have chosen for our Atomic Structures And The Periodic Table Project is

LEARNING OBJECTIVES The learning objectives of this experiment are to. . . ! ! determine changes in enthalpy and entropy of the reaction of zinc with copper sulfate using two methods: electrochemistry and calorimetry. compare the enthalpy values obtained by the two methods. BACKGROUND Thermodynamics is concerned with energy changes that occur in chemical and physical process es. The enthalpy and entropy changes of a system undergoing such processes are interrelated by the change in free energy, ªG, according to the equation

To determine the enthalpy change for the displacement reaction between zinc powder and copper (II) sulphate solution.