CHEM 1201 Chapter : Preparation And Properties Of H2 And O2 Gasses

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azuremammoth471

15 Mar 2019

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Document Summary

Water is the most abundant compound on the surface of the earth, and hydrogen is the most abundant element in the universe; 93% of all atoms in the universe are hydrogen atoms. The objective of this experiment was to prepare hydrogen and oxygen gases and to examine some of the properties of these gases. To do this, the oxygen and hydrogen must be burned off of a hydrogen peroxide. The first test tube with h2 only and the fire blown out only caused the fire to go out . The second tube with h2 only and an open flame made a small pop noise. The reaction from the first tube was mainly due embers third tube with a mixture of oxygen and hydrogen gas, with an open flame made an were blown out due to lack of oxygen. The reaction from the second tube was caused because more oxygen was entered from the open flame.

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Please answer the questions 13-16 marked as the âREPORT FOR EXPERIMENT 3â by reading the first 4 pictures if it helps.

EXPERIMENT 3 Preparation and Properties of Oxygen MATERIALS AND EQUIPMENT Solids: candles, magnesium (Mg) strips, dry yeast, fine steel wool (Fe), wood splints. Solution: 3 percent hydrogen peroxide (HOp), pneumatic trough, 20 to 25 em length rubber tubing, 25 X 200 mm ignition tube, five wide-mouth (gas-collecting) bottles, five glass cover plates. DISCUSSION Oxygen is the most abundant and widespread of all the elements in the earth's crust. It occurs both as free oxygen gas and combined in compounds with other elements. Free oxygen gas is diatomic and has the formula O2 Oxygen is found combined with more elements than any other single element, and it will combine with all the elements except some of the noble gases. Water is 88.9 percent oxygen by mass and the atmosphere is about 21 percent oxygen by vol- ume. Oxygen gas is colorless and odorless, and is only very slightly soluble in water, a prop- erty important to its collection in this experiment. Oxygen may be obtained by decomposing a variety of oxygen-containing compoun of these are mercury(ID oxide (HgO, mercuric oxide), leadIV) oxide (PbO2, lead dioxide), potas- sium chlorate (KCIO,), potassium nitrate (KNO,), hydrogen peroxide (H02), and water (H,O). In this experiment oxygen is produced by decomposing hydrogen peroxide, and five bottles of oxygen will be collected by the downward displacement of water. After collection, some the physical and chemical properties of oxygen will be observed. A. Decomposition of Hydrogen Peroxide to Generate Oxygen Hydrogen peroxide decomposes very slowly at room temperature. The rate of decomposition is greatly increased by adding a catalyst, manganese dioxide. Although manganese dioxide contains oxygen, it is not decomposed under conditions of this experiment. These equations represent the changes that occur Word Equation: Hydrogen peroxide Water + Oxygen Formula Equation: 2H,0,la)H,oN)+ 0g) B. Collection of Oxygen The oxygen is collected by a method known as the downward displacement of water. The gas is conducted from a generator to a bottle of water inverted in a pneumatic trough

Just need help with a few questions from my lab!

Lab Notes:

Experiment 1:

Tube 1: No bubbles produced

Tube 2: Bubbles produced, slowly and sporadically

Tube 3: Bubbles produced, quickly and constantly

Tube 4: Bubbles produced, slowly and sporadically

Tube 5: No bubbles produced

Optimum temp for catalase activity: 40 C

Experiment 2:

Tube 1: 4 min, 42.38 sec

Tube 2: 5 min, 4.37 sec

Tube 3: 5 min, 18.26 sec

Tube 4: 5 min, 28.36 sec

Concentration: 10 mL 3% hydrogen peroxide

Experiment 3:

Tube 1: No bubbles produced

Tube 2: Bubbles produced, quickly

Tube 3: No bubbles produced

Optimum pH for catalase activity: pH 6 buffer

Lab Questions

Experiment 1:

1. Why did catalase fail to function at 80 Â°C?

2. What caused the bubbles to form when you added the catalase to the hydrogen peroxide and water mixture at 40 Â°C?

A. Catalase activity heated the solution to its boiling point.

B. Hydrogen gas formed during the formation of hydrogen peroxide.

C. Oxygen gas formed during the decomposition of hydrogen peroxide.

D. The constant temperature bath heated the solution to its boiling point.

Experiment 2

3. Before the catalase concentration was saturated with hydrogen peroxide, why did the enzyme function vary with substrate concentration?

4. Why did the catalase function level off when different hydrogen peroxide concentrations were tested?

Experiment 3

5. Why did catalase only function in a limited range of pH values?

6. Based on your results from this lab, would you expect the hydrogen peroxide you buy from the store to bubble like soda when you open it?

A. Yes, hydrogen peroxide is only stable in the presence of catalase. Without it, store bought hydrogen peroxide decomposes quickly.

B. No, catalase sped up the rate of the reaction. Store bought hydrogen peroxide will decompose into water and oxygen gas much too slowly for visible bubbles to form.

C .No, hydrogen peroxide can only decompose into water and oxygen gas in the presence of catalase.

D. Yes, catalase had little effect on hydrogen peroxide decomposition. It would bubble quickly no matter what.

7. Do the optimal conditions for catalase functioning that you found correspond with the conditions in the mammalian liver where it came from?

		A. Yes, catalase worked best at a neutral pH and temperature of 40 Â°C, both of which are close to mammalian tissue conditions.
		B. No, catalase functions best at a much higher pH than in mammalian tissue and at a much lower temperature.
		C. Yes, catalase functions best at the same low pH and temperature as occurs in the mammalian tissue.
		D. No, catalase functions best at several very different pHs and temperatures, while the pH and temperature of mammalian tissue does not fluctuate. 8. How much slower would hydrogen peroxide likely be decomposed if catalase was not available in cells? A. 100 times B. 1,000 times C. 10 times D. 1,000,000 times 9. What are the enzyme, substrate, and product in these experiments? 10. What role does catalase play in the mammalian liver, or any other cell it is found in? Thank you!!