Wednesday, January 29, 2020

Involves and acid and a metal Essay Example for Free

Involves and acid and a metal Essay The Problem: To investigate one of the factors affecting the rate of reaction between a metal and an acid. Background Knowledge: The balanced equation for the reaction that takes place between magnesium and hydrochloric acid is: Mg + 2HCl == MgCl + Cl From this equation, we can already see that it involves and acid and a metal, therefore: Acid + metal == salt + hydrogen The ionisation equation of the hydrochloric acid is: HCl(aq) == H + Cl This experiment will demonstrate the breaking of bonds. Bonds break in order to allow certain atoms to re-arrange before the new bonds are formed. When magnesium reacts with the hydrochloric acid, a particle of this acid must collide with a particle of the magnesium with adequate energy in order to break the bonds between the magnesium and the hydrochloric acid. This is known as the Collision Theory. The collisions between the particles must collide more often and with more sufficient energy in order for the rate of reaction to increase. Although, not every collision produces a successful reaction as they require a certain amount of energy to break bonds. This is called activation energy. The rate of a chemical reaction refers to the speed at which it happens, and different metals react at various rates. The progress of a reaction can be measured by the rate of a formation of a product or by the decrease of reactants. There are four main factors that can be varied to affect the rate of reaction between magnesium and acid: 1. Surface area (of the reactants) 2. Concentration (of the reactant) 3. Temperature 4. The presence of a specific catalyst If the surface area were increased by using a magnesium powder, then the reaction would speed up, as there are more particles that are able to collide with the hydrochloric acid. The products of a reaction are formed as a result of the collisions between the reactant particles. Consequently, if the concentration of a solution is increased, collisions are more likely to occur. The more often the particles collide, the higher the chance that a reaction will take place. Subsequently, the rate of a chemical reaction increases if the concentration of the reactant is also increased. This is also because the rate is proportional to the concentration. E. g. Diagram to illustrate a high concentration and a low concentration: When the temperature at which the reaction is carried out is increased, the energy of the particles also increases. As a result of this, the particles move much faster allowing them to collide more often with other particles. Therefore, as there are more collisions and these collisions are more energetic, the rate of reaction increases. Catalysts are used to speed up a reaction. These biological catalysts are extremely specific, therefore only speed up certain reactions. Every chemical reaction taking place has an exclusive enzyme catalyst (an enzyme is a protein molecule produced in a living cell.) A catalyst will decrease the activation energy and forms an alternative path to help the collisions to be more successful. Safety: As I will be using glass conical flasks and burettes, I will be very careful when handling them in case I harm myself or others by dropping them. The hydrochloric acid is also corrosive, which means that it is able to eat away at materials that it is within contact with. Again, I should handle this carefully and ensure that there are no spillages. Water seems quite harmless, but if I spill any, it is possible that someone may skid or trip on it. For safety precautions, I will wear goggles and an overall and also tie my hair back. Method:   I will begin by attatching a plastic burette clamp to a clamp stand at a practical height to begin my experiment.   I will then fill my water tub approximately 1/2 full with water, and place it next to my clamp stand (so that the burette clamp is able to hole the burette above the tub. )   Next, I will fill my burette with tap water above 50cmi   and attach it to my clamp stand using the burette clamp. Very quickly, I will swiftly turn the burette upside down and speedily submerge it under the water. Afterwards, I will produce the solution of hydrochloric acid and water using separate measuring cylinders. I will remove the bung that is stopping the conical flask, and pour in the measurements of hydrochloric acid and water. I will then drop the magnesium ribbon (which will be cut using scissors), replace the bung and swirl the solution for a second, whilst starting the stop clock. I will take readings every 10 seconds. Diagram: Apparatus:   Burette   Delivery tube Clamp stand   Burette clamp   Magnesium tape   Distilled water   Stop clock   Conical flask Measuring cylinders (at least 2).

Tuesday, January 21, 2020

She :: essays research papers

Khadijah and her brother was home alone on a Monday night. No they were not trying to have a wild party. They were waiting by the phone expecting a call from there parent. I know this sounds strange, teenagers waiting for a call from their parents. But this was not a "Is the house okay" call. There Aunt Marla was in the Hospice House for the terminally ill. They wanted to know how she was doing and was every thing okay. When the phone rung they ran to it like horses at the race track. It was their father telling them that their Aunt was doing fine and will have to stay there a couple of months. They felt relive to hear the good news, but Khadijah knew something was not right. As she got in the bed it felt kind of strange like someone was in it. (Let's not forget this is the same bed Khadijah use to share with her Aunt when she lived with her family.) Khadijah went to sleep with her Aunt Marla in her mind. The next morning Khadijah woke up feeling like something was wrong. She got dress as usual and went down stairs for breakfast. But she did not sit to the table with her brothers. Instead she sat in the rocking chair her Aunt read her stories in. When her mother came down stairs she ask was everything was okay. Khadijah said "yes everything is fine." Everything was not fine, but Khadijah did not no what was wrong yet. When Khadijah got out of the chair to take her bowl to the kitchen she notice it started to rock on its own. She thought nothing of it and guess it came from her getting up real fast. Every morning Khadijah's mother takes her and her brother to school. And on the way there is a graveyard. Khadijah hardly ever looks at the graveyard when she passes by, but something about it today made her look. It look like it had some kind of glow to it. As she pass by Khadijah said "Somebody's dead", her brother Carl said " No duh! The people in the graveyard are.". But Khadijah was not talking about the people in the graveyard. Then Khadijah ask her mother what time was it. Her mother said it was 8 o'clock. Her brother ask "Why does it matter?

Monday, January 13, 2020

Abraham Lincoln and the Self-Made Myth Essay

An ambitious ascent from a poor Illinois farm boy to occupying the highest political office during one of Americas most turbulent times makes for the literature of hero worship. In the essay entitled Abraham Lincoln the self-made myth Rich Hofstadter challenges the reader to penetrate beneath the surface of the American political tradions and investigate the event and actions that contributed to the Lincoln Myth. To begin with Hofstadter states that one of Lincolnà ¢Ã¢â€š ¬Ã¢â€ž ¢s most endearing qualisties to Americans was his humble origins and the fact that, à ¢Ã¢â€š ¬Ã…“Lincoln was a preeminent example of that self-help which Americans have always so admired,à ¢Ã¢â€š ¬Ã‚  (121). But he further goes on to state that Lincoln used this to his advantage. First in his campaign speeches always eluding to himself as humble Abraham Lincoln and in the way he addressed his own wife in public as à ¢Ã¢â€š ¬Ã…“motherà ¢Ã¢â€š ¬Ã‚  (122). See more: Foot Binding In China essay He received distinguished guests in shirtsleeves, and once during his presidency hailed a soldier out of the ranks with the cry, à ¢Ã¢â€š ¬Ã…“Bub! Bub!à ¢Ã¢â€š ¬Ã‚  The concept of the self-made, simple man played well with the American public thus became à ¢Ã¢â€š ¬Ã…“fully absorbed into his political being,à ¢Ã¢â€š ¬Ã‚  (124). Historical novels and fictionalized biographies about Lincoln would be amiss of the greater portion of its contents were not dedicated to the slavery issue. Many only give, à ¢Ã¢â€š ¬Ã…“a tiresome celebration of the America past with a progressive interpretation of American history of her-worship and national self-congratulation,à ¢Ã¢â€š ¬Ã‚  (Forward 2). In Hostadterà ¢Ã¢â€š ¬Ã¢â€ž ¢s essay he discusses the slavery issue not with a sentimental approach but with critical analysis. Lincoln was a Southerner by birth. He grew up in communities in Illinois where slavery was rare. Laws against runaway slaves were in force when Lincoln served in the s tate legislature. It was here that Lincoln made his first public statement on slavery by voting against a proslavery resolution.

Saturday, January 4, 2020

Visiting Museums - Free Essay Example

Sample details Pages: 1 Words: 299 Downloads: 4 Date added: 2017/09/18 Category Art Essay Type Argumentative essay Did you like this example? Some people find visiting museums boring as a form of entertainment, while others believe that the role of museums is to educate people, not entertain. Discuss, what is your opinion? In our world today, there is a wide variety of museums where people can travel to and see differently interesting things. Some people state that visiting museums is only a form of recreation; others disagree, arguing that museums play a role in education. In fact, each of these arguments has its own validity. Firstly, museums such as art and music can offer people with a wide range of entertainment activities. For example, they often organise traditional music events performed by local or other famous artists that people can attend to and enjoy to some extent. Another point is that many visitors nowadays may choose to come to museums just for pleasure or as one of the activities that they take part in their holiday trips. This, therefore, makes museums a place to entertain in people leisure time. On the other hand, the establishment of a particular museum like history, science, or oceanography is usually attached to educational purposes. As can be seen, school and university students and teachers are always the guests of museums because the places are where they can discover and obtain a large amount of information related to their studies and teaching. In addition, there are a number of seminars and conferences held at museums that are informative and necessary for scholars and experts in their fields of research. In this way, museums prove the supporting role in human education. In conclusion, visiting museums is clearly seen as both means of entertainment and education. However, from my viewpoint, people should perceive the value of museums in enhancing their own knowledge about the world they live in. Don’t waste time! Our writers will create an original "Visiting Museums" essay for you Create order