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Science balance equa
| Question | Answer |
|---|---|
| Question 1: What are the products in the chemical reaction of the burning of the candle and what are the reactants? | |
| Products (The substances that are created): Heat, light, Carbon Dioxide, water vapor. | |
| Reactants (The substances that combine together): Wax, oxygen in the air | |
| Question 2: What is the law of conservation of mass and what does it mean? | |
| The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction. Meaning that matter will still exist in the same amount - but sometimes in a chemical reaction that changes to a new element/compound! | |
| Question 3: What is a balanced equation and what does it mean? | |
| A balanced equation is an equation where all the atoms in the reactants form the products so the mass of the reactants and the products is the same. No new atoms are created, and no atoms are destroyed. | |
| Question 4: In the vinegar and baking soda chemical reaction what are the products and what are the reactants? | |
| Reactants: Vinegar, Baking Soda | |
| Products: Carbon Dioxide Gas (CO2) | |
| Question 5: In the vinegar and baking soda experiment, what happened when we added detergent as a product and why did we do this? | |
| We use the detergent to give us a better idea of the amount of CO2 that is produced because now it exists in bubbles! This gives us a clear visual on the reactants and remains balanced as an equation visually (instead of the atoms being lost to the air - | |
| Question 6: How many molecules of each element are on each side of this equation? | |
| 3 carbon atoms, 5 hydrogen atoms, 5 oxygen atoms, 1 sodium atom | |
| C2H2O2 + NaHCO3 | |
| The number underneath denotes the number of molecules of that element present. | |
| Question 7: Is this a balanced equation, why/why not? | |
| C6H5C2H5 + O2 = C6H5OH + CO2 + H2O | |
| Left side = 8 Carbon, 10 Hydrogen, 2 Oxygen | |
| Right Side= 7 Carbon, 7 Hydrogen, 3 Oxygen | |
| Not Balanced! | |
| Question 8: Is this a balanced equation, why/why not? | |
| C2H5 + O4 = COH3 + CO2 + H2O | |
| Left Side= 2 Carbon, 5 Hydrogen, 4 Oxygen | |
| Right Side= 2 Carbon, 5 Hydrogen, 4 Oxygen | |
| Is Balanced - Same amount of each element on each side! | |
| Question 9: Why do all equations need to be balanced? | |
| All equations need to be balanced because matter cannot be created or destroyed - it will always exist in the same amount! | |
| Question 10: What happens to a chemical reaction when it is heated up and why? | |
| When heat is added to a chemical reaction, the reaction happens faster. This speeding up of the reaction causes the molecules to move faster as thermal energy is added. The average speed of the reaction is increased. | |
| Question 11: Why do both of these liquids (Aqueous solutions) form a solid? | |
| A precipitate is an insoluble solid that forms when two solutions are combined and react chemically. Insoluble means that the solid will not dissolve. | |
| Question 12: When the glow sticks are placed in different temperature water, which one glows brightest? Why? | |
| The glow stick in the hot water is going to glow brighter. The more thermal energy added to a chemical reaction, makes the reaction happen faster, thus making the glow stick burn brighter. | |
| Question 13: What is a catalyst and what is the catalyst in elephant toothpaste? | |
| A catalyst is a substance that can help the reactants in a chemical reaction react with each other faster. In the case of elephant toothpaste, potassium iodide (KI), yeast, and/or warm water can act as catalysts to speed up the reaction. | |
| Question 14: Explain what is happening in this image: | |
| This image shows the molecular decomposition of hydrogen peroxide. When hydrogen peroxide decomposes, 2 molecules of hydrogen peroxide produce 2 molecules of water and 1 molecule of oxygen. | |
| Question 15: How is adding salt to the aluminum similar to adding yeast to the hydrogen peroxide? | |
| Both adding salt to aluminum and adding yeast to hydrogen peroxide can be seen as catalysts. Adding yeast helps the hydrogen peroxide decompose faster, and adding salt helps the aluminum react with the copper II sulfate. | |
| Question 16: What numbers are on the pH Scale and what do these numbers indicate? | |
| The pH scale ranges from 0 to 14. | |
| Numbers below 7 indicate acidity, with 0 being the most acidic. | |
| Number 7 indicates neutrality. | |
| Numbers above 7 indicate alkalinity, with 14 being the most alkaline. | |
| Question 17: Fill in the blanks: | |
| It takes energy to break bonds. If a reaction is exothermic, more energy is released when the bonds of the products are formed than it takes to break the bonds of the reactants. | |
| A chemical reaction involves the breaking of bonds in the reactants and the forming of bonds in the products. | |
| Question 18: What is a coefficient in a chemical equation? | |
| Coefficients are integers written in front of each molecular formula in a chemical equation, and they indicate the quantity of each molecule that is reacted or produced in a chemical equation. | |
| Question 19: Fill in the blanks: | |
| Coefficients should be adjusted to equalize the number of atoms for each element, always using integers. | |
| Question 20: What is the law of conservation of charge? | |
| The law of conservation of charge states that the total electric charge in an isolated system never changes. The net quantity of electric charge, the amount of positive charge minus the amount of negative charge in the universe, is always conserved. | |
| Question 21: How will you know when the solution is neutralized? | |
| The color of the solution will be similar to the color of the control. If the solution turns blue, it has gone from an acid, past neutral, and is now a base. If this happens, try adding one or more drops of citric acid until the color is close to neutral. | |
| Question 22: Fill in the blanks: | |
| Adding an acid increases the concentration of H3O+ ions in the solution. Adding a base decreases the concentration of H3O+ ions in the solution. | |
| Question 23: Which of the colors on this chart are neutral, acidic, and basic? | |
| Red, orange to yellow is acidic. | |
| Green is neutral. | |
| Blue to darker blue is basic. |
Created by:
m.blount
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