The Percentage by Mass of Calcium Carbonate in Eggshells Essay Example for Free

The Percentage by Mass of Calcium Carbonate in Eggshells Essay The purpose of this experiment is to determine the percentage by mass of calcium carbonate in eggshells. Introduction To avoid the breakage of eggs before reaching market, the eggshells needs to be as strong as possible. The strength of eggshells is mainly determined by the percentage of calcium carbonate in it. In order to monitor the quality of eggshells, the following experiment has to be done to determine the percentage of calcium carbonate in eggshells. In this experiment, back titration is used. First, excess acid is reacted with the calcium carbonate in eggshells: 2HCl(aq) + CaCO3(s) CaCl2(aq) + H2O(l)+ CO2(g) Later, if we can find out the number of mole of unreacted acid, number of mole of calcium carbonate can then be found out. The number of mole of unreacted acid can be found by titration with the following reaction: HCl(aq) + NaOH(aq) H2O(l) + NaCl(aq) Percentage by mass of calcium carbonate in eggshell can then be calculated by the following formula: % by mass of CaCO3 = Requirements eggshell burette, 50 cm3, and stand pipette, 25 cm3 pipette filler methyl orange indicator M NaOH solution, standardized 1 M hydrochloric acid, standardized ethanol wash-bottle with de-ionized water mortar and pestle forceps safety spectacles 2 beakers, 100 cm3 volumetric flask, 250 cm3 filter funnel, small magnetic stirrer pH meter electronic balance Procedures 1. The attached membrane of the eggshell was removed carefully by forceps and the remaining eggshell was ground into a fine po wder with mortar and pestle. 2. 2 g of powder was weighed accurately by the difference on an electronic balance and put into a beaker on a magnetic stirrer.

Free Essay: Restructuring Relationships Shakespeares King Lear :: King Lear essays

Restructuring Relationships in King Lear The play of "King Lear" is about a search for personal identity. In the historical period in which this play is set, the social structure was set in order of things closest to Heaven. Therefore, on Earth, the king was at the top, followed by his noblemen and going all the way down to the basest of objects such as rocks and dirt. This structure was set up by the people, and by going by the premise that anything that is man made is imperfect, this system cannot exist for long without conflict. Through tattered clothes small vices do appear; Robes and furred gowns hide all. Plate sin with gold, And the strong lance of justice hurtles breaks; (IV, vi). The chaos that occurs in "King Lear" is due the reshaping of bonds within the society. Thus naturally, bonds must be broken, kept and most importantly, formed. This rearrangement of bonds is necessary to Lear understanding his personal identity. Bonds that are broken include those relations between King Lear and his two eldest daughters (Regan and Goneril), between Glouster and Edmund and also between Edmund and Edgar. Lear and Cordelia; Lear and Kent; Glouster and Edgar include those bonds that are existent at both the beginning and conclusion of the play. By the ending of the play, Lear is able to come to terms with himself and with nature. For the rearrangement of the bonds, it is necessary that those based on money, power, land, and deception be to abandoned. In the case of Lear and Goneril and Regan, his two daughters have deceived their father for their personal gain. Furthermore, they had not intended to keep the bond with their father once they had what they wanted. Goneril states "We must do something, and i' th' heat." (I, i, 355), meaning that they wish to take more power upon themselves while they can. By his two of his daughters betraying him, Lear was able to gain insight that he is not as respected as he perceives himself to be. The relationship broken between Edmund his half- bother, Edgar and father, Glouster is similarly deteriorated in the interest of material items. By the end of the play, Edgar has recognized who is brother really is and when he has confronted him says "the more th' hast wronged me...

1492: Conquest of Paradise and Indians Essay

1492: Conquest of Paradise is a movie directed by Ridley Scott and it was released in 1992. The main character Christopher Columbus was played by Gerard Depardieu and the movie was about his attempt to find a way to go to India by sailing west. The movie begins with Columbus teaching his son how the earth is round. Then Columbus thinks about the ways to get to India and that the best way was to go west. The people in Salamanca agreed to seeing his proposal all they do is laugh at it and challenge his idea. Even though the council rejected the idea he goes to Queen Elizabeth I which is played by Sigourney Weaver, and she gave him a chance. This other man wanted to help him but wanted money in return but Columbus did not accept and was to become a monk but the queen did not allow it and the queen supported the trip. They use this pendulum this to help them navigate and to find what degree latitude or longitude they are at. See more:  Unemployment – problems and solutions essay It has been weeks and the men think that they have gone off track and they do not trust in Columbus. They finally reach land and they go and explore until they find the indians. At first the indians are scary and Columbus’s plan does not involve force. They did not really find any gold except the artifacts the Indian’ gave them. The spanish were treated as gods. About 39 men stayed behind to build a fort while they go back to Spain cause the captain called Mendez played by Kevin Dunn, had a fever that would not go away. When they get to Spain they get applauded and and now he wants to go back with 7 ships and 1500 men. So he goes back to the West Indies and all his men are dead and the village they were at was burned down to the core. He wants peace with the Indians and so the Indians help bring in this bell and they help construct this fort and village. Then the Indians were put to find gold and they had to go turn it in everyday and one did not find anything and this man comes and chops his hand off and that starts a war with the natives. So the natives attach and burn down what they built but in reality an actual spaniard burnt it down. Two spaniards make allies with the Indian, one commits suicide then they start cooperating and this storm comes and everything is destroyed. Then at the end his son Fernando writes of his dad’s voyage. The movie is in the main character’s perspective which is Christopher Columbus. The message of the story is that if there is a will there is a way. Columbus did not give up even though the university did not support  him. The movie relates really well to the themes of politics, social, economical, and cultural. Social is about two types of people interacting, in this case the Indians and Spaniards. You see the culture of the Indians. From what i know about Christopher Columbus’s story I did not find any historical inaccuracies, except how he did 4 trips and they only show him doing 2 trips. This movie has a great value in advancing my knowledge of history. There are barely any historical inaccuracies (I believe), it stuck to the real history. I do not believe that there are not any drawbacks, this movie is very accurate and it is a valuable source.

How to Quiet a Class Without Yelling

When you get home from work, do you often feel hoarse from telling the kids to stop talking and exhausted from trying, in vain, to keep your kids on task? Do you fantasize about a quiet classroom in your private moments? Discipline and classroom management are, by far the top battles that you must win in the classroom. Without focused and relatively quiet students, you might as well forget about hard work and significant academic achievement. Believe it or not, it is possible to quiet your students and keep them on task with simple nonverbal routines that save your voice and your sanity. The key here is to get creative and do not expect one routine to work forever. Many times, effectiveness wears off with time; so feel free to rotate through the various methods listed below. Here are some teacher-tested student discipline strategies that meet the objective of maintaining a quiet classroom with ease. The Music Box Buy an inexpensive music box. (Rumor has it that you can find one at Target for approximately $12.99!) Each morning, wind the music box up completely. Tell the students that, whenever they are noisy or off task, you will open the music box and let the music play until they quiet down and get back to work. If at the end of the day, there is any music left, the kids receive some type of reward. Maybe they can earn tickets for a weekly drawing or a few minutes towards end-of-the-week free play time. Be creative and find the perfect no-cost reward that your students will really want to quiet down for. Kids love this game and will quiet down immediately as you reach towards the music box. The Quiet Game   Somehow, when you just add the word game to your request, the kids will generally snap right into line. They get 3 seconds to make as much noise as they want and then, at your signal, they become silent for as long as possible. Students who make noise receive dirty looks and peer pressure to quiet down again. You can set the timer and tell the kids that you going to see how long they can stay quiet this time. You might be surprised at how well this simple technique works! Eye the Clock Each time your students get too loud eye the clock or your watch. Let the students know that whatever time they waste by being noisy, you will subtract from their recess or other free time. This usually works really well because the kids dont want to miss recess time. Keep track of the time lost (down to the second!) and hold the class accountable. Otherwise, your empty threats will soon be discovered and this trick wont work at all. But, once your kids see you mean what you say, a mere glance towards the clock will be enough to quiet them down. This is a great technique for substitute teachers to have in their back pockets! Its quick and easy and will work in any situation! Hands Up Another nonverbal way to quiet your class is to simply raise your hand. When your students see that your hand is raised, they too will raise their hands. Hands up mean stop talking and pay attention to the teacher. As each child notices the cue and quiets down, a wave of hand-raising will envelop the room and you will soon have the whole class attention. A twist on this is to raise your hand and count one finger at a time. By the time you get to five, the class needs to be quietly paying attention to you and your directions. You may want to quietly count to five along with the visual cue of your fingers. Your students will soon get used to this routine and it should be pretty quick and easy to quiet them down. Advice The key to any successful classroom management plan is to think carefully about the goals you want to achieve and act confidently. You are the teacher. You are in charge. If you dont believe this underlying precept wholeheartedly, the kids will sense your hesitation and act on that feeling. Consciously design your discipline routines and teach them explicitly. Students love routines as much as we do. Make your hours in the classroom as productive and peaceful as possible. Both you and the kids will flourish under such circumstances!