Nicolas

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The purpose of the lab is to explain about chemical reactions.

The chemical reaction is a process that leads to the transformation of one set of chemical substances to another

There are few different evidences for chemical reactions. There are color change, precipitation, gas production, changes in temperature, and changes in properties.

My original prediction was that Alka-Seltzer dissolves in the water will dissolve the fastest in the hot tap and dissolve the slowest in the ice water and I had no idea of the color change.

Our group tried 3 times to do the experiment. Once with a mixture of 4oz of ice and 4oz of water, once with 8oz of room temperature water, and once with 8oz of hot tap water.

For the first trial we used hot tap water to dissolve Alka-Seltzer. It took 20 seconds to dissolve it and the temperature was 78.1 deg C before we dissolved it, and after it was completely dissolved, the temperature was 80.4 deg C.

Next, we dissolved the Alka-Seltzer in room temperature water. It took 64 seconds to dissolve it and before dissolving it, the temperature was 17.3 deg C, and after it was dissolved, it was 17.2 deg C.

At last, we dissolved Alka-Seltzer in ice water. The starting temperature was 1.6 deg C and it was 0.5 after it dissolved. The amount of time it took to dissolve was 165 seconds.



In each trial, when the Alka-Seltzer was dissolving, the color of the water was changing. Also, the amount of time it took for the tablet to dissolve affected the rate at which the water color changed.

In 80 deg C water, tablet dissolves about 5times faster than the 0 deg C water.

The purpose of the lab was met because I found out that the Alka-Seltzer in the hot tap water dissolves quicker than the tablet in the 0 deg C ice water.

Release of Gas(Experiment 3) In this experiment, a new substance is often indicated by release of gas or liquid. What they prepared for this experiment are zipper-lock plastic bag, paper tower or napkin, 1/4 cup of baking soda, 1/2 cup of vinegar, and 4/1 cup of warm water. After they prepared all these, they warned us to wear proper protection for our eyes and our clothing. Next, they put sodium bicarbonate in to a paper towel or a napkin and folded in an envelope shape. Secondly, they combined water and vinegar in a zip-lock plastic bag. Lastly, they put the sodium bicarbonate envelope into a zip-lock plastic bag and quickly sealed it. Right after doing that, stuff that have been mixed started making bubbles inside the plastic bag and soon, bag burst. There were no variables which controlled the rate of chemical reaction. The reason why the bag burst was because of the carbon dioxide. Baking soda and vinegar was mixed and made a explosion. I think this experiment takes place in everyday life because mixture of baking soda and vinegar or similar kind of substances could be seen a lot in our lives. If I could, I'd really want to try this experiment especially because I want to see the burst. I learned about science that we can actually experience the chemical reaction that when few substances mixes, it can explode even though it's a small explosion. It was interesting to watch this video and found out why it burst.

media type="custom" key="12401510" Our class did an activity an activity called "chemical bonding" yesterday. For this activity, we made compounds like H2O NaCl by valence the electrons. Not only these two, but there were total 16 different kinds of compounds. We had to click each compound and click and drag the elements to make it fit into the compounds. After we finish making a compound, we had to draw the elements with dot diagram and draw the dots in different color. So this activity wasn't so hard, wasn't so fun, but just a normal school activity.

**Mixture and Solution Lab** My hypothesis was that solid would dissolve in water better than the liquid. The reason for it was just because somehow I didn’t even know that liquid can even dissolve. I thought solid was only substances that could dissolve in water. Overall, I was totally wrong. Well, many different kinds of solids were soluble. Three of them were soluble and two of them weren’t. For liquid, two of them were soluble and one of them wasn’t. So the solid substances and the liquid substances neither dissolved better in water. Since water is polar, different types of substances which has different molecules reacts all differently and that kinds of different reactions made different results of soluble and non soluble. Essay Questions on Mixtures and Solutions The coolant in a car's radiator protects the engine from damage is because the coolant a solution that absorbs heat from the engine. Antifreeze lowers the freezing point and makes boiling point increase. By increasing the boiling point, the water inside the engine would't boil at 100 deg C so the engine won't get any damage. Particles like salt which is an ionic compound, and like sugar which is a molecular compound dissolves in water in totally different days. For an ionic compound like salt, solid is exposed and it can dissolve in it. In the other hand, a molecular compound like sugar breaks up to neutral molecules when it dissolves, which means sugar dissolves better than salt because they both dissolves in different ways. We have different methods to separate a suspension like water and sand, and separate a solution like water and sugar. Sugar has too small molecules to filter it. We use filter to separate suspensions like water and sand because sand has big enough molecules. In the other hand we have to boil the sugar water and evaporate it to separate them or at least heat them up enough to evaporate and separate them. Hypothesis: I think solids will dissolve better than liquids because I don’t know how liquid can dissolve in water.
 * **Substance** || **Solid/Liquid** || **Soluble/Non Soluble** ||
 * Salt || Solid || Soluble ||
 * Sugar || Solid || Soluble ||
 * Vinegar || Liquid || Soluble ||
 * Rubbing alcohol || liquid || Soluble ||
 * Pepper || Solid || Non soluble(suspension) ||
 * Powdered chalk || Solid || Non soluble ||
 * Baking soda || Solid || soluble ||
 * Corn starch || Solid || soluble ||
 * Vegetable oil || liquid || Non soluble ||

Results: Our group for the experiment had one trial for nine substances. The purpose of this experiment was to see if solid will dissolve in water better or if liquid will dissolve better in water. When we put a solid substance such as sugar and salt, the substance fall down to the bottom of the water and after we stirred it, it mixed with water so we couldn’t see it. Well because they were saturated, it looked like it was non soluble but we searched it and it was soluble. When we put liquid in to the water such as vegetable oil and rubbing alcohol, one of them was soluble the other one wasn’t. They were both kind of obvious.

Conclusion: My hypothesis was that was that solid would dissolve better than liquid. My hypothesis was wrong. Neither of them really dissolved better than the other. There were some soluble substances for solid and liquid, and there were some non-soluble substances for both. The water is polar and substances dissolve when they meet water depends on what substance that is. Also it’s hard to know what’s soluble or not, so we have to put them in the water.