Wednesday, August 17, 2016

Fruit Voltage


Batteries need three parts. A cathode (positive electrode), and anode (negative
electrode), and an electrolyte (material to push the electrons). When making a fruit battery,
the juiciness of the fruit or vegetable is the electrolyte, and the two metals inserted into
the fruit are the electrodes

Material

1. Fruits: Orange and lemon
2. Metals: copper (penny), nickel (nickel), iron (regular nail), zinc (galvanized nail),
3. Volt meter
4. Amp meter 
5. crocodile wire clips
6. battery




Procedure

Roll the fruit a little to make it a little juicier in the inside. Insert one electrode material
into the juicy part of the fruit. Insert a second electrode into the juicy part of the fruit, but
not so the two electrodes touch. Then, connect the electrodes to the meters with crocodile wire clip. 


Orange










Lemon






















Electrolysis Experiment


Material

- Petri dish
- Universal indicator solution
- 58.5 g Sodium Chloride (NaCl)
- 9 volt battery
- electrode wires with alligator clips


Procedure

1. Fill a petri dish with distilled water
2. Add a small amount of salt and stir until dissolved
3. Add enough universal indicator to give a rich green colour
4. Attach each of the wire alligator clips to one end pencil lead. Attach the other ends of the electrodes to the battery poles, the red wire to the positive pole, the black wire to the negative pole. Turn the projector on.
5. As electrolysis progresses, colour changes will begin to occur
6. Place a niobium magnet in the middle and discuss what happens.


Material









Procedure







   

Sunday, July 17, 2016

DNA Necklace


Materials

1. 2 mL plastic cup

2. 15- mL tube
3. 2 mL of cell lysis solution

4. pipet
5. ethanol



Instructions

1. Take 2 mL  of sport drink into your mouth and swish it around for 1 minute. As you swish, gently and continuously scrape the inside of your cheeks with your teeth to help release cheek cells.

2. Spit the sport drink with collected cell back into the plastic cup.

3. Carefully pour the solution into a labeled 15-mL tube.

4. Add 2 mL of cell lysis solution into the collected cheek cells and invert the tube 5 times.

5. Then, use the pipet to drop a 70% ethanol by running it down the inside of the tube. Add the ethanol until the solution reaches to 14 mL .

6. Watch closely as wispy strands of translucent DNA begin to clump together where the ethanol layer meets the cell lysate layer.

7. Place the 15-mL tube in the test tube rack and let it stands undisturbed for a minimum for 10 minutes. During this time, DNA will continue to precipitate out of the solution and extend like a ribbon through the ethanol layer.



Material






Result




Sunday, June 19, 2016

Titration is a technique that chemists use to determine the unknown concentration of a known solution

In the case of the unknown concentration of acid, we can use a known concentration of hydroxide base. The reaction is called “neutralization”

Materials:
  • 50 mL Buret with clamp
  • Phenolphthalein indicator
  • 250 mL Erlenmeyer flasks
  • Buret funnel
  • 250 mL beaker
  • 25 mL volumetric pipette
  • Pipette bulb

Procedure:
1. Set up the clamp and 50 mL phenolpthalein in the Buret funnel .
2. Mixed the 250 mL indicator solution with acid in beaker
3. Drop the base drops by drops cautiously, while you drop, keep stiring the solution
4.When the acid solution start to turn into pink, stop.
5. Record data



DATA 



weak acid
Strong acid

Trial 1
Trial 2
Trial 3
Trial 4
Initial buret volume [mL]
50
50
50
50
Final buret volume [mL]
50-11.2
50-19.4
50-19.3
50-19.2
Volume of base [L]
11.2
19.4
19.3
19.2
Moles of base [mol]
0.1
0.1
0.1
0.1
Volume of acid [L]
0.25
0.25
0.25
0.25
Moles of acid [mol]
(calculation)