Wednesday, 22 February 2017

This year is a great year for me. I have done many labs experiment. I looking forward to the next year lab.




 

Thursday, 2 February 2017

Objective
To understand that a leaf which is left in the light contains the starch by using the iodine solution to test.
Equipment

Procedure
   1. Add water to a beaker and then warm it but not boil.
   2. Put a leaf in the beaker containing warm water and wait about 2 minutes.
   3. Bring a test tube containing 99% alcohol solution and put the leaf in that test tube, followed by putting the test tube in the beaker.
   4. Wait until the green color is visible in the water.
   5. Drop the iodine solution on the leaf and see the changes.
   6. Record the data.











Observation
The color of a tested leaf changed to a bit black when dropped the iodine solution, compared to the original leaf, iodine didn't change the color of a leaf.
Discussion questions:
1)  Why do we boil the leaf?
     We have to stop a chemical reaction.
2)  What is the leaf texture like after boiling?
     The texture of a leaf become smooth and soft.
3)  Why do we use ethanol on the leaf after boiling?
     We have to extract chlorophyll with hot ethanol. 
4)  What is the color of the water after boiling the leaf?  why?  Why did some people get pink brown water?
     The color becomes a little turbid because the element of a leaf is extracted by hot water.  In my opinion, the leaf may be boiled until almost all of an element is extracted.
5)  When you test for starch with the iodine, why does the paper turn black?
     Because the paper is made from a wood which has the component of a starch.
6)  What happens to the iodine test on the unboiled leaf?  why?
     There is nothing happening to the unboiled because the leaf has the skin protection made of a cell wall.

Wednesday, 25 January 2017

Problem: How to graft plants
Objectives: To experiment whether the branches of other same species plants can connect with one branch at the node.
Hypothesis: I think the branch will connect together.
Materials:
1. scissors
2. Knife
3. rope
4. Clay
Procedure:
1. Prepare all equipment
2. Cut two branches of two plants into v-shape at the node
3. Bring one branch of another plant connects to the one plant which is cut.
4. Hold the branches with a clay.
5. Bind around the clay with a rope.

Data


Conclusion
From the research, most people have succeeded. Both clay and a rope are in fixed position with holding the branch. Attached branch still alive because the leaf is still green.
Questions
1.  Why do we use clay?
     Connecting them together by using clay help to make sure that they are in a fixed position or don't move apart.
2.  Why do we cut at the node?  what is the node?
     The node is where the branch can grow. It is beneficial for a new grafted branch to supply a nutrient supported by a vascular bundle.
3.  Why do we use string to tie it?
     The original shape of clay might be changed, so we use a string to hold.
4.  Any observations?
Observation
- Both clay and a rope are in fixed position with holding the branch.
- Attached branch still alive because the leaf is still green.
Discussion
My group graft a plant in a safe place where there are no risky circumstances such as a rain to plant
Data after 5 days

Wednesday, 4 January 2017

Question
 1.
2. With the room temperature, the heat distributes into the molecules of solution, so the graph doesn't start with zero.
3. Both trends continue increasing constantly above zero until around 90, then it is slowly rising to the boiling point.
4. I think the graph will stay the same at the boiling point of 96 degree Celsius.

Experimental Photos






Amazing New TASTE ICE CREAM ===> SALTY VANILLA Ice cream
GRAPH

Monday, 28 November 2016

1.  Is there a difference in reaction time between using your fingers and your arms to catch the ruler?
Ans. It is obvious that fingers and arms catch the ruler differently in fall distance.
a)  why or why not?
Ans. This is because the signal takes different period of time from brain to different organs, the muscle of finger responses slower than the muscle of arm.
b)  if there is no difference, how close together are the numbers?

2)  What do you think would happen to the reaction time, if you said the word monkey and then, dropped the ruler?
Ans. Giving an attention to say the word monkey, I would lose a concentration to the ruler drop, taking longer time to catch the ruler.
3)  what would be the difference in reaction time, if the person was saying the alphabet and you dropped the ruler?
Ans. Reciting the alphabet takes more greater concentration than saying the word of monkey, so I would take longer time than catching the ruler while saying the word of monkey.
4.  What is the different sensitivities of the forefinger, arm, and nape of neck?
Ans. The response of nape of neck is slower the forefinger and arm.

Wednesday, 23 November 2016

CALORIMETRY - - - - "Burn Lab"


Objective: To calculate the number of calories of energy contained in serving food items and compare to real number as determined by the manufacture.
Equipment:
- Test tube & holder
- Ring stand
- Thermometer & Clamp
- Lighter
- Evaporating dish
- Pieces of Lays
Data: 






Discussion/Analysis Questions
1. Is the reaction (the combustion of the chip) exothermic or endothermic? Explain your answer.
Ans. In fact, combustion reaction is always exothermic because the heat is transferred to surrounding which temperature is increased.

2. Describe the reactant and products of the chemical reaction. Was the reactant (chip)
completely consumed? What evidence supports your answer?

Ans. According to the combustion reaction, the reactants are pieces of lays and Oxygen while products are burned lays, CO2 and heat. I believed that there is leftover which is still not completely consumed.

3. What was the purpose of having the water in the test tube in this lab?

Ans. The water is used as the medium because we didn't measure the temperature of frame.

4. Was all of the heat that was released by the food absorbed by the water in the test tube (use data to support your answer)? How can the experimental equipment be improved to decrease the percent error?

The heat is distributed to other medium such as air because this is open system.