1. X pure material is solid at room temperature. If the substance is heated to 230'C melted gradually. When cooled to room temperature, the liquid can not be frozen.a. Is X possible of an element or compound. Explain!b. Is it a chemical change occurs? If it can be said to undergo a change endotherm, based on the information provided?c. Can it be said that the fluid is an element, based on the information provided?
Answer,:
a.) is unsure, because sulfur at temperatures below 95.5 c he will be called stable with sulfur or sulfur rombik having three axes of unequal length, and above 95.5 c he would form monoclinic crystals and turn into a frozen at 25 c is monoclinic, while Robik not freeze.
b.) chemical changes that occur are due to changes in endothermic compound X to convert solids to liquid heat transfer resulting from the environment to the system (heat absorbed by the system from its environment), a marked drop in the ambient temperature around the system.
c.) yes I think, because the fluid including elements At room temperature (25 C) elements can be solid, liquid or gas, and the elements of X changes as heated
2. When the candle burned 10gr weight in oxygen, carbon dioxide and water vapor formed by the combustion of heavy over this 10gr.was match case with the law of mass conversation. Explain!
Answer:
Law kekelan mass or more known lavoiser law, laws are based on the equivalent equation, where the equation is no reactant atom = number of atoms the reaction proceeds, the lavoiser law reads: "The mass of substances before and after the reaction is the same"Since mass and energy related, in a system that gets / expend energy, the mass of a very small amount will be made / lost from the system. However, in almost all events that involve changes in energy, law of conservation of mass can be used because the mass has changed very little.
candle when it reacts with oxygen will mengasilkan product mass more than the mass of candles before the reaction, it is because the mass of wax and oxygen are united, it was the cause of the mass of carbon dioxide and water vapor which is derived more from the mass of wax before the reaction.
3. When carbon burns under a limited amount of oxygen, it forms two gaseous compounds. Suggest a way to differentiate the two compounds with one another.?
.Answer:
CO Carbon monoxide, a gas that is colorless, odorless, and tasteless. It consists of one carbon atom covalently bonded to one oxygen atom. In this bond, there are two covalent and one coordinate covalent bonds between carbon and CO2 oksigen.sedangkan many atoms were found in the results of the combustion in motor vehicles,Furthermore, to determine the difference between CO and CO2 can be seen by reacting with lime water, if the CO2 gas in reaksikan with lime water, there will be a white precipitate (CaCo3), while the CO gas reacted with lime no white precipitate occurred.
4. After mendeev preparing the periodic table, he concluded that the atomic weights of some elements was the wrong decision, and this conclusion appears to be true. How mendeev able to predict that the atomic weight of a few is wrong? Why predictions are not always right. Explain!
Answer.
Dmitri Ivanovich Mendeleev in 1869 observations of 65 known elements and get the result that properties of elements are a periodic function of the relative atomic mass. Certain properties will be repeated periodically if unsurunsur ordered by relative atomic mass increases. The next Mendeleev placed elements with similar properties in the vertical column called class. These elements have also been prepared by the increase relative atomic mass and placed in a column called period. Mendeleev developed the periodic table which can be seen in the following table:
Answer,:
a.) is unsure, because sulfur at temperatures below 95.5 c he will be called stable with sulfur or sulfur rombik having three axes of unequal length, and above 95.5 c he would form monoclinic crystals and turn into a frozen at 25 c is monoclinic, while Robik not freeze.
b.) chemical changes that occur are due to changes in endothermic compound X to convert solids to liquid heat transfer resulting from the environment to the system (heat absorbed by the system from its environment), a marked drop in the ambient temperature around the system.
c.) yes I think, because the fluid including elements At room temperature (25 C) elements can be solid, liquid or gas, and the elements of X changes as heated
2. When the candle burned 10gr weight in oxygen, carbon dioxide and water vapor formed by the combustion of heavy over this 10gr.was match case with the law of mass conversation. Explain!
Answer:
Law kekelan mass or more known lavoiser law, laws are based on the equivalent equation, where the equation is no reactant atom = number of atoms the reaction proceeds, the lavoiser law reads: "The mass of substances before and after the reaction is the same"Since mass and energy related, in a system that gets / expend energy, the mass of a very small amount will be made / lost from the system. However, in almost all events that involve changes in energy, law of conservation of mass can be used because the mass has changed very little.
candle when it reacts with oxygen will mengasilkan product mass more than the mass of candles before the reaction, it is because the mass of wax and oxygen are united, it was the cause of the mass of carbon dioxide and water vapor which is derived more from the mass of wax before the reaction.
3. When carbon burns under a limited amount of oxygen, it forms two gaseous compounds. Suggest a way to differentiate the two compounds with one another.?
.Answer:
CO Carbon monoxide, a gas that is colorless, odorless, and tasteless. It consists of one carbon atom covalently bonded to one oxygen atom. In this bond, there are two covalent and one coordinate covalent bonds between carbon and CO2 oksigen.sedangkan many atoms were found in the results of the combustion in motor vehicles,Furthermore, to determine the difference between CO and CO2 can be seen by reacting with lime water, if the CO2 gas in reaksikan with lime water, there will be a white precipitate (CaCo3), while the CO gas reacted with lime no white precipitate occurred.
4. After mendeev preparing the periodic table, he concluded that the atomic weights of some elements was the wrong decision, and this conclusion appears to be true. How mendeev able to predict that the atomic weight of a few is wrong? Why predictions are not always right. Explain!
Answer.
Dmitri Ivanovich Mendeleev in 1869 observations of 65 known elements and get the result that properties of elements are a periodic function of the relative atomic mass. Certain properties will be repeated periodically if unsurunsur ordered by relative atomic mass increases. The next Mendeleev placed elements with similar properties in the vertical column called class. These elements have also been prepared by the increase relative atomic mass and placed in a column called period. Mendeleev developed the periodic table which can be seen in the following table:
Mendeleev deliberately emptied a few places to establish similar properties in the group. Some boxes also intentionally left blank because Mendeleev sure there's an element that has not been known for has not been found, one of the new elements in accordance with the prophecy germanium Mendeleev was previously named ekasilikon by Mendeleev.namun also has the disadvantage of the use of the elements of the Mendeleyev, ie1. the placement of Te (128) before I (127) are arranged upside down, and the existence of several different elements that are located in the same vertical column2. period is not the same length, and explain why not.3. Mass difference of successive elements are not always 2, but the range between 1 and 4, making it difficult to predict the mass of an element that has not been known exactly.4. Deviations hydrogen from the other elements are not described,5. Valence elements of more than one class of his unpredictable.
5) When the mercury chloride solution is added to a solution of silver nitrate, a white solid forms. Identification of a white solid and write a balanced equation for the reaction!
Answer.:
HgCl2 + + 2AgNo3 2AgCl Hg (No3) 2
The resulting white powder / solid precipitate is (AgCl)
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