Saturday, January 25, 2020

Displacement Reaction :: Papers

Displacement Reaction The aim of my experiment is to find out what happens to the heat of the zinc and copper sulphate solution when one of the variables is changed. Key variables:  § amount of copper sulphate solution  § amount of zinc I am going to investigate what happens to the temperature of the zinc and copper sulphate solution as the amount of zinc is increased. The equation to show this reaction is: Zn + CuSO4  ® ZnSO4 + Cu The enthalpy change for the reaction is:  ²H = -217kJ mole  ¹ This means that if 1 mole of solution is used of each substance, the heat given off will be 217,000 Joules. Apparatus:  § 1 test tube  § 20ml of copper sulphate solution for each experiment  § Zinc  § Rubber bung  § Thermometer Prediction: I think that as the amount of zinc is increased, the temperature of the solution will also increase. I have used the following formula to predict some results of this experiment. q = Q mc where q = temperature rise, Q = quantity of heat, m = mass of solution (20g) and c = the specific heat capacity of water which = 4.18Jg  ¹K  ¹. 65g Zinc  ® 217000 joules 1g Zinc  ® 217000 = 3338 joules 65 Therefore for 1g of zinc: 3338 =39 °c rise 20x4.18 I can now use this formula proportionately to predict results for my investigation. For 0.3g of zinc: 0.3 x 39 = 12 °c rise For 0.5g of zinc: 0.5 x 39 = 19.5 °c rise For 0.7g of zinc: 0.7 x 39 = 27.3 °c rise For 0.9g of zinc: 0.9 x 39 = 35.1 °c rise I have used this information in order to predict the results of the temperature rise I expect to see as the amount of zinc is increased. I have also used this information to plan my experiment.

Friday, January 17, 2020

Human Digestion Essay

The salivary glands are the first to react in the digestive process, which are usually triggered by either the sight or the smell of food. Food enters the digestive tract through the mouth where the teeth, tongue, and salivary glands help moisten and break down the food within minutes. The food then becomes something called a bolus, which will travel through the pharynx, then through the esophagus, and into the stomach. As the food travels through the pharynx the epiglottis is in place to prevent food from entering the lungs. Once the bolus enters the stomach it is broken down with acid secretions. The food is partially digested within the stomach. The bolus then becomes chyme (a semiliquid food). Chyme usually leaves the stomach during a time frame of 2-6 hours. The small intestine is where most of the digestion and nutrient absorption takes place with the help of secretions from the liver, gallbladder, and pancreas. The small intestine consists of three parts: the duodenum, the jejunum, and the ileum. Anything that is not absorbed in the small intestine then enters the large intestine travelling through the sphincter. The sphincter prevents any of the remaining food from re-entering the small intestine. The large intestine is made up of two major parts: the colon and the rectum. The colon aids in the absorption of leftover water, vitamins, or minerals. Anything left over after this process is considered waste product (feces) and is then excreted from the body via the anus, which  is attached to the colon. Reference Human Digestion Activity. Retrieved August 21, 2009 from http://corptrain.phoenix.edu/axia/sci241/sci241-digestivetract.html