Thursday, 28 March 2013, 16:55
CHEMISTRY FORM FIVE CHAPTER 1 : RATE OF REACTION
THE REVIEW OF CHEMISTRY FORM FIVE CHAPTER 1 : RATE OF REACTION
1. Still under the misconception of how volume of certain reactants affect the amount of products formed if given two or more dissimilar volumes and concentrations. Need further explanations. Need thorough understanding and grasp of the reaction graphs.
2. Need to consistently memorize the specificity of catalyst on certain uses.
3. The reaction between Calcium Carbonate and Sulphuric Acid which is the most common without the need of catalyst.
4. 3 common experiments for this chapter involving in experimenting the factors affecting rate of reaction which is.
Experiment I - To study the size factor (can use to experiment the concentration factor)
Materials needed - powdered and coarse marble calcium carbonate, 0.1 mol dm-3 hydrochloric acid, water
Apparatus needed - Burette, 100cm3 measuring cylinder(to measure hcl), basin, 150cm3 conical flask, stopper fitted with a delivery tube, electronic balance(to weigh the caco3), stopwatch
Experiment II - To study the concentration factor (can use for temperature but with the heating apparatus)
Materials - 0.2 mol dm-3 sodium thiosulphate Na2S2O3 solution, 1.0 mol dm-3 sulphuric acid, white paper with the mark 'X' at the center
Apparatus - 150 cm3 conical flask, 50 cm3 measuring cylinder(to measure Na2S2O3),10 cm3 measuring cylinder(to measure acid), stopwatch
Experiment III - To study the temperature factor
Materials - 0.2 mol dm-3 sodium thiosulphate Na2S2O3 solution, 1.0 mol dm-3 sulphuric acid, white paper with the mark 'X' at the center
Apparatus - 150 cm3 conical flask, 50 cm3 measuring cylinder(to measure Na2S2O3),10 cm3 measuring cylinder(to measure acid), stopwatch, thermometer, Bunsen burner, tripod stand, wire gauze
Labels: chapetr 1, form five, rate of reaction
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Wednesday, 28 November 2012, 21:36
BIOLOGY CHAPTER 7 : RESPIRATION
BIOLOGY CHAPTER 7 : RESPIRATION
Subtopic : Respiratory Structures and Breathing Mechanisms in Animals.
Okay so basically there are a few organisms which possess particular respiratory structures and their own adaptive breathing mechanisms. These are namely Protozoa(paramecium/amoeba), Amphibians(frog), Insect(grasshopper), Fish.
Protozoa :
Okay so, here we have a few examples like paramecium and amoeba but we'll take amoeba as a supreme exhibit.
Look at those jelly-looking amoeba, looks light and almost transparent. Here are the Q's & A's.
1. Does it have any respiratory structures?
No. It doesn't. See how transparent and almost empty it is inside? The whole external surface of the amoeba IS already serve as the respiratory surface. No need structures lah.
2. How does oxygen and carbon dioxide flow in and out of it?
They simply diffuse in and out through the plasma membrane down the concentration gradient.
3. Does it has bigger surface area to volume ratio?
Definitely. See how curly and waggly the body parts are? Duh.
Next, Insects.
Grasshoppers. Ideally. Maybe it's a whole lot conceivable than the rest given that it's breathing mechanism looks already pretty complicated itself. So whatever.
So here we have the - whatever that is of a grasshopper. You can see the spiracles, air sacs, tracheole, trachea(tracheal tubes). These are the main components.
The opening and closing of the inlet is actually controlled by valves. You get that from here.
The tubes are covered with rings of chitin so as to prevent it from collapsing or become deflated. Now let's see how the process goes. Q's & A's,let us have it :)
1. How does the air enter?
Air goes into the spiracle in which it is endorsed by the contraction/relaxation of the abdominal muscle. Fundamentally, contract and relax to force air in and out respectively.
2. What happens during inhalation and exhalation?
Inhalation : abdominal muscle relaxes, spiracle's valves open, pressure in tracheae decreases, air goes in. As opposed to that during the exhalation process.
3. Define tracheal system
A network of small tubes where oxygen is absorbed directly from atmosphere to every cell of the body.
So you see, there are no complicated process at all. As a matter of fact, air actually goes directly to every cell to be absorbed! Unlike human whose respiratory mechanism is way more difficult to seize.
3. Amphibians
Okay, moving on. Here we're going to take frog as an example. Since it's the only example found in the textbook.
Basically a frog has 3 different ways in order to exchange gases.
1. CUTANEOUS RESPIRATION (MAIN SUPPLY OF OXYGEN)
Directly through the thin, permeable, moist and richly supplied with blood capillaries skin. Oxygen dissolves easily into the blood capillaries.
2. BUCCAL RESPIRATION
As generally explained by the above diagram, there are four steps identified :
1. Inspiration - where the nostril opens, glottis opens
2. Filling air inside the buccal cavity - nostril opens, floor of buccal cavity(mouth) lowers, glottis closes
3. Forcing air into the lungs - nostril closes, mouth raises, glottis opens as the air is forced in
4. Expiration - nostril opens, mouth opens, glottis opens
3. PULMONARY RESPIRATION (WHEN THE OTHER BOTH METHODS ARE DEFICIENT IN OXYGEN SUPPLY)
This is most likely to happen in and of the lungs. Each frog has a pair of lungs which are moist, and has a network of blood capies on tiny alveolus.
Oxygen dissolves through the moisture surface of the epithelium before it diffuses into the thin epithelium and into the blood capies.
Finally, now it's fish.
- editing later, haven't seized the entire thing yet.
Labels: chapter 7, form four, respiration
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