16-LAB Conservation of Mass LAB Report PDF

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Lab report about the conservation of mass...

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SNC2D Name:

Date:

Conservation of Mass Lab PROBLEM (for parts 1 & 2) How does the mass of reactants and products change in a chemical reaction? HYPOTHESIS (for parts 1 & 2): Write a hypothesis in “If…then…” format to predict whether the mass of the products should increase, decrease, or stay the same. If two substances combine and have a chemical reaction, then the total mass of the reactants will equal the total mass of the products.

MATERIALS (for part 1 & 2) ▪

safety goggles

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tweezers

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100 mL beaker

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flint lighter

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test tube

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bunsen burner

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hydrochloric acid

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wooden splint

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solid piece of zinc metal

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electronic balance

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iron (III) chloride solution

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graduated cylinder

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sodium hydroxide solution

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test tube stopper

PROCEDURE FOR PART 2:

Group Procedure – Copy onto your own sheet below 1. They pulled back and secured long hair and loose clothing 2. They took off any jewelry they had on 3. They placed their cellphones somewhere safe and far from the area of the experiment 4. They washed their hands 5. They dried their hands 6. They went to an open space to do their experiment 7. They put on their safety goggles 8. They got a desk 9. They cleaned the desk 10. They gathered a graduated cylinder, a test tube, a test tube stopper, hydrochloric acid, a 100 mL beaker, a solid piece of zinc metal, a piece of tissue paper, a flint lighter and an electronic balance 11. They placed the materials on the side of the desk but away from the ledge 12. They wrote the physical properties of the hydrochloric acid and the zinc 13. They plugged in the electronic balance 14. They poured some hydrochloric acid in a 100 mL beaker 15. They measure 5mL of hydrochloric acid in the graduated cylinder 16. They placed the graduated cylinder with its stopper on the electronic balance and measured the mass of the hydrochloric acid 17. They wrote down the mass of the hydrochloric acid with a piece of paper and a pencil

SNC2D 18. They placed the zinc on a small tissue paper on the electronic balance 19. They measured and recorded the mass of the zinc with a piece of paper and a pencil 20. They opened the graduated cylinder and quickly dropped the zinc inside 21. Quickly after they dropped the zinc into the graduated cylinder, they quickly put the test tube stopper on top 22. They made sure the test tube stopper was tightly on the test tube 23. They tilted the graduated cylinder sideways to that the zinc was surrounded by the hydrochloric acid 24. They recorded their observations of the reaction 25. They waited 10 minutes 26. After 10 minutes, they weighed the graduated cylinder 27. They measured and recorded the total mass of the graduated cylinder 28. They unplugged the electronic balance 29. They grabbed their flint lighter 30. They quickly took off the test tube stopper and placed the test tube on the table 31. They quickly used the flint lighter over the top of the test tube and fire ignited because of the hydrogen gas that was produced and then the fire extinguish 32. They disposed the contents into a waste container 33. They washed the graduated cylinder, the beaker and the test tube 34. They put the graduated cylinder, the test tube, the test tube stopper, the beaker, the flint lighter and the electronic balance away 35. They threw out the tissue paper 36. They washed their hand and dried them 37. They removed their safety goggles 38. They recorded and explained the results of the experiment 39. They concluded the experiment

OBSERVATIONS PART 1 – Use the table provided to record all observations. Table 1: Observations of the Properties and Mass of Reactants Before and After a Reaction has Taken Place

Name of Reactants

Iron (III) chloride solution

Physical Properties of Reactants -

Sodium hydroxide solution

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It was a liquid It was a very light mix of the colours orange and yellow It had no odour It has a low viscosity It was a liquid It had no odour It had no colour It was transparent

Mass BEFORE the reaction (Reactants) 176.37g

Observation(s) of Reaction

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No bubbles were formed The iron precipitated and reacted with the hydroxide and started to form into crystals The crystals were a dark orange The sodium and chloride from the iron (III) chloride solution mixed together but

Mass AFTER the reaction (Products) 176.37g

SNC2D -

It has a low viscosity -

had no physical changes The sodium chloride stayed on top of the iron (III) hydroxide

PART 2 OBSERVATIONS – Create a table (or tables) to record all observations.

Table 2: Observations of the Properties and Mass of Reactants Before and After a Reaction has Taken Place

Name of Reactants

Hydrochlor ic acid

Physical Properties of Reactants -

A solid piece of zinc metal

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It was a liquid It was transparent It had no odour It has a low viscosity It was a solid piece of metal It was light It was circular It had no odour It was a silvery-whit e colour with a blue tinge It was lustrous It was smooth

Mass BEFORE the reaction (Reactants) 160.08g

Observation(s) of Reaction

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-

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The zinc reacted and the hydrochloric acid reacted with each other cause the acid to fizz and create many small bubbles The chemical reaction caused popping sounds The zinc turned black The zinc dissolved partly Hydrogen gas was produced (you could see the smoke) The hydrochloric acid because cloudy

Mass AFTER the reaction (Products) 160.08g

SNC2D ANALYSIS & DISCUSSION (for part 1 & 2)– What were the major trends in the observations recorded? What do these trends mean in terms of conservation of mass in chemical reactions? (i.e. do the trends make sense? Why or why not?) The major trends in the experiment were that the total mass of iron (III) chloride solution and sodium hydroxide solution before and after it reacted with each other stayed the same and, it was the same outcome when hydrochloric solution and zinc combined. In the experiment, the iron (III) chloride solution was a liquid with a very light mix of the colours orange and yellow. It had no odour and, it had a low viscosity. The sodium hydroxide solution was a transparent liquid with no fragrance, no colour and a low viscosity. The weight of the two solutions was measured separately, and the total mass of the substances was 176.37g. Then when the two solutions mixed in a test tube, the iron precipitated into the hydroxide and created iron(III) hydroxide, which had no odour and had a low viscosity. Also, the chemical reaction produced crystals with a dark mix of orange and brown to form in the iron(III) hydroxide solution. Also, sodium chloride was produced on top of the iron(III) hydroxide solution and, it was transparent, it had no odour and a low viscosity. Then the substances were weighed again, and their total mass was the same before the chemical reaction. Then for the experiment with hydrochloric acid and zinc, the hydrochloric acid was a transparent liquid with no odour and a low viscosity. The zinc was a solid, smooth, circular piece of metal that was light, it had no fragrance, it was a silvery-white colour with a blue tinge, and it was lustrous. Before the two substances combined, their mass was recorded, and the total weight was 160.08g. Then when the two substances combined in a test tube, the chemical reaction caused many small bubbles to appear, popping sounds and, it also created zinc chloride and hydrogen gas. The zinc did not dissolve completely, but the zinc did shrink and turned black while the hydrochloric acid became cloudy. Then the substances were weighed again before removing the test tube stopper, and their total mass was the same before the chemical reaction. Their weight was measured because the test tube contained hydrogen gas, which was tested by opening the test tube and using a flint lighter. If hydrogen gas was produced, a fire would ignite and that precisely happened. Hydrogen gas was also part of the substance's weight, so opening the test tube would have caused the substance to lose some mass. The mass of the iron (III) chloride solution and the sodium hydroxide solution before and after it reacted with each other stayed the same and, the same thing happened with the mass of the hydrochloric solution and the weight of the zinc. These trends make sense because two substances are combining to create something new but, that means they are emerging together and that their masses will merge too. There was only one source of error in the two experiments, which was that the test tube stopper was not on properly during the trial with hydrochloric solution and zinc. Therefore that experiment needed to be done once more because the hydrogen gas escaped, and its mass was part of the weight of the new substance. Without the weight of the solution, the hypothesis would not be able to be verified correctly. Therefore, the experiment with the hydrochloric solution and zinc happened a second time and ensured that the stopper was tightened to the test tube.

CONCLUSION (for part 1 & 2) – Follow the 3 Step process!

In conclusion, the hypothesis was verified. The hypothesis stated that if two substances combine and have a chemical reaction, then the total mass of the reactants will equal the total mass of the products. The observation of combining iron (III) chloride and sodium hydroxide and also combining hydrochloric solution and zinc, their total weight before and after they had a chemical reaction with each other, it stayed the same. These results show that the Law of Conservation of Mass is verified, that the mass of the products is equal to the mass of the reactants, which proves that the hypothesis is correct. It proves that if two substances combine and have a chemical reaction, then the total mass of the reactants will equal the total mass of the products. Therefore the hypothesis was verified....