Criado por Moon Tintaglia
quase 10 anos atrás
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Questão | Responda |
The COLOR of a sample is an example of a (physical/chemical) property because ________. | ☑ physical Does not change the chemical make up of the sample |
Baking a cake is an example of a (physical/chemical) change because ________. | ☑ physical Very difficult to reverse, changes the chemical makeup of the substances |
Defiine: -Chemical Reaction | a process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction |
Write the difference between an endothermic and exothermic reaction. Which one uses more energy than is released? | An endothermic absorbs energy while an exothermic releases energy. |
What is a product in a chemical reaction? | A product in chemical reaction lies on the right side of the arrow and is what is produced by the reactants. |
What is a reactant in a chemical equation? | A reactant in a chemical equation lies on the left side of the arrow and helps to produce the product. |
What is the Law of Conservation of Mass? | Mass is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants. |
Recall the Conservation of Mass Lab. What evidences of chemical reaction occurred? Did they all happen at the exact time? | Evidence of a chemical reaction was ☑Gas is Produced ☑Exothermic temperature change ☑Change of Color ☑Changes in properties |
How does the data from the Conservation of Mass Lab verify Lavosier's Law? If the ziplock bag had not been sealed, do you think the data from the experiment would have verified the law? | The data verified Lavosier's Law since the weight was about the same. Since some of the weight was gas, it may have been lighter since the gas was trying to escape and pushing upwards. If the ziplock bag had not been sealed, the gas would have escaped and the data would not have proved Lavosier's Law. |
2H2 + O2 = 2H2O Explain why this equation is a good example of the law of conservation of mass. | On both sides of the equation, there is the same number of each element. No atoms are lost or gained. Therefore, no weight is lost or gained. |
Are H2O and 2HO representations of the same compound? Explain. | These are not representations of the same compound because the coefficient '2' in 2HO are applied to both H and O making there 2 H and 2 O unlike the other equation H2O where there are 2 H but only 1 O. |
What is needed to break bonds in a chemical reaction? | To restore the amount of energy there was initially. |
What does a coefficient in chemical equations denote? | Coefficients are multiplied to the current amount or atoms of each element there are. |
What do subscripts in chemical equations denote? | Subscripts show you how many atoms of each element there are. |
How many Carbon atoms are in the following compound? CH3(CH2)4CH3 | There are 6 Carbon Atoms. |
Balance the equation: ____N2 + _____H2 ➡ ______NH3 | 1N2 + 3H2 ➡ 2NH3 |
In a chemical equation, the products are to the (right/left) of the arrow? | ☑left |
Define mixture | When elements are combined but the chemical make up is not changed |
How is a mixture different from a compound? | A mixture is different from a compound because mixtures have elements mixed together but the chemical make up is not changed. Compound's combined element's chemical make ups are changed |
Is a state change a physical or chemical change? Explain using water as an example. | It depends on the situation. With water, it is a physical change. At room temperature, water is a liquid. However, water can freeze or boil. When a certain two liquids are combined, they may create a solid and then it is a chemical change. |
What is a precipitate? | A precipitate is when two liquids create a solid at room temperature. |
When an antacid tablet is placed in water, what type of change will occur? What evidence will confirm your hypothesis? | This is a chemical change because the antacid tablet usually produces gas (fizzes) when placed in the water. |
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