#2 Entry- The Marble Run (Techexploration on Gravitiational Energy)

Today we had to build a track for the marble to roll down but the slower it is the better.

We were given several materials such as pins, a board, straws small, medium and large-sized marbles. Using these materials we had to build a track so that the marbles could roll down slowly.

Reflection

1.    How well did the marble stay on its pathway?

The marble stayed on its path well. It did not roll of the board halfway and completed its route.

2.    How well did it turn the corners?

It turned its corners quite well too. It did not stop halfway because of barriers.

3.    How long did it take the marble to complete its journey?

It took 3 seconds to complete its journey.

4.    What was its overall speed?

Its overall speed is 3 seconds

5.    What other factors affect the performance of your marble?

The clay that we used was sticky, and the pins were used as barriers

6.    How might your design be improved?

We should have used straws instead of clay becau

se the clay made the board and the marble sticky. Furthermore, our marble rolled down really quickly as the clay did not really slow it down. We could also use the pins as barriers to slow the marble down instead. The size of the marble affected our result as well. We used the biggest marble provided, hence, it would have the most kinetic energy and this will cause it to roll down faster.

# Entry 1- The Tallest Free Standing Structure

Today, we started our integrated Science module.

The task for use was to make a structure using solely newspaper (x4 sheets), that is both tall and stable at the same time.

It was challenging as the newspaper was flimsy and it tore easily. Our end product did not work out because of several issues:
1. The gravity was not low and not in the centre
2. The surface areas for the base was too small

We were too focused on trying to make the structure tall, that we forgot to consider how stable the structure would be. This led to the downfall of our structure and it could not balance because it was too tall and leaned to one side.

However, from this experiment, I learnt how important it is to consider several factors and decide how to build the structure first before actually carrying out the actual plan.

#14- Kinetic Particle Theory: Practical 2

Finally an experiment after several lessons of SIP!

Today we conducted experiments to find out the properties of alkalis.

Steps:

1. Place a piece of blue litmus paper, red litmus paper and universal indicator paper on a white tile
2. Use a dopper to carefully add a drop of dilute sodium hydroxide to all three strips of indicator.
3. Repeat the experiment using dilute potassium hydroxide and ammonia water

Observations:

For all 3 alkalis, the red litmus paper turned blue, while the blue litmus paper remained blue. For dilute hydroxide solution and sodium hydroxide solution, the universal indicator paper turned from green to bright violet. For ammonia, the universal indicator turned from green to bright blue.

Steps:

1. Using a clean test tube, add dilute sodium hydroxide to the test tube to 2cm in height.
2. Light the bunsen burner 
3. Carefully add 1 spatula of ammonium chloride to the test tube
4. Warm the test tube gently over a bunsen flame
5. Moisten a piece of red litmus paper and place it at the mouth of the test tube
6. Gently fan some of the gas towards your nose

Observation

Effervescence is observed. Colorless and pungent gas evolved which turned damp/moist red litmus paper blue. Gas in ammonia gas.

Steps:

1. Using a clean boiling tube, add dilute hydrochloric acid up to 2cm in height.
2. Add 3 drops of universal indicator solution to the boiling tube
3. Using a dropper, add 1 drop of dilute sodium hydroxide to the acid in the boiling tube and gently shake the boiling tube
4. 
   

#13 Entry- Kinetic Particles Theory (Chemical Changes) Practical 1

Haven't been posting for a long time!

Today, we did two main practicals, than consisted of many small procedures that were both easy and fun to do.

So, for the first experiment, we had to investigate if changes of matter can be brought about by light if the substance of material is light sensitive.

Steps:

1. Soak the filter paper with sodium chloride solution (NaCl)
2. Place the filter paper on a clean white tile
3. Drip 4 drops of silver nitrate solution all over the the filter paper. White precipitate will form on the filter paper. Ensure that the white precipitate covers the filter paper.
4. Quickly place the opaque object on top of the filter paper, covering some of the white precipitate
5. Place the paper in bright light for 15-20 minutes.

After the experiment was done and after awhile, we observed violet coloured stains on the filter paper.

Violet-Coloured Filter Paper

For the next part, Mr Foo demonstrated as heating was required.

Steps:

1. Add a level spatula of the copper (ll) nitrate solid into a test tube
2. Gently heat the solid in the test tube over a bunsen flame
3. Record any observations

thermal decompostion

Next experiment that the teacher did was cool because it involves lighting a fire in water!

Steps:

1. In a beaker of soap water, bubble gas from the gas tap into the soap water
2. Scoop a handful of bubbles
3. Light a lighter at the bubbles

Didn't manage to get a picture though.

Explanation: Particles move faster, hence there is more spaces between the particles. The substance will then be able to fill up the spaces between the molecules. Hence The water and the fire are actually separated. Thus the water cannot extinguish the fire.

After that, we conducted an experiment by ourselves

Steps:

1. Fill a boiling tube with potassium iodine solution and lead nitrilate solution
2. Add 5 drops of lead nitrate solution to the boiling tube
3. Record any observations
4. Add water to the boiling tube until it is half full
5. Heat the resulting mixture to obtain a near colourless solution 
6. Allow the boiling tubes to cool on a test tube rack for approximately 10 minutes then place it in a beaker of water
7. Record any observation

*steps 5-7 were conducted by the teacher

when 2 colourless liquids were mixed together, they formed a bright yellow substance

While being heated, the yellow substance dissolves and forms a solution (clear)

lastly, the acids and whatnot

the end!

#12 Entry- Experiments KPT

Today we did several experiments to prove the KPT assumptions right, and to learn more about it.

The first experiment we did was to heat up Sodium Chloride, and observe its appearance at first, than during heating, after heating and after cooling.

Sodium Chloride was grainy and white in color. After heating, (for a very, very long time), it melted into a colorless liquid. When we removed it from the heat source for just awhile, the liquid form of NaCl change state back into liquid and it was a little foamy.

The coolest one that we saw  was Magnesium oxide. It sparked of a bright white light when it was heated! It was really cool.

Heating the Magnesium...

and the white bright light

Heating up  NaCl

#11 Entry- Experiment: Investigating Diffusion of Gases and Liquids

Today, we did simple experiments to help us understand the concept Diffusion.

First, Mr Foo showed us the experiment that involved the heating of sold iodine, and after sublimation, to iodine vapour . It was really cool as the iodine was purple and the gas was purple. At first, the gas was a dark shade of purple, but after awhile, it faded as it slowly diffused with the air, and hence, turned a lighter shade.

Diffusion
So what is diffusion?
I would define diffusion as the movement particles from an area of higher concentration to that of a lower concentration till it reaches an equilibrium.

Diffusion tells us that matter is made up of small particles which are in constant motion and random direction.

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Next, there was an experiment that showed the relationship between of gas with rate of diffusion. 2 highly corrosive acids were involved: hydrochloric acid and ammonia gas, hence we were not allowed to be in contact with it.

This is a diagram of the experiment (as i did not take a picture :P)

Though it wasn't a very successful experiment.


Next, we conducted a very simple experiment by ourselves.

First, we poured sand and beans respectively into 2 separate test tubes. Later on we mixed them together.

Two separate test tubes

mixture

The initial volume is 50 ml each. Hence, I predicted that there will be 70cm3 of it left. However, there was 90cm3 left instead. This shows that there are spaces between the beans.

The last experiment was mixing ethanol and water. Since they are miscible, the volume decreased after we shook it. 

Starring Min and Sneha, and of course, the tube!

Thats all!

#10 Entry- Experiment: Crystallization

Today we had a chance to make our very own crystals!

It was really fun and cool.

What is Crystallization?
Basically, crystallization is the most common method used to purify soluble solids. There are many ways to carry out crystallization. The seeding method allows you to grow a large single crystal, others allow you to grow many crystals at a time. By controlling the variables such as cooling rate and evaporation rate, the size and shape of the crystals can be controlled.

Some conditions:
Firstly, the solid must be soluble in water. Secondly, the solubility of the substance should change with changing temperature. (eg solubility increases as temperature increases). Thirdly, the solution used should be saturated with the solute.

For the experiment we conducted, we purified copper (ll) sulphate crystals and investigate the effect of the cooling rate on the size of the crystals obtained.

Steps:

1. Heat about 20cm3 of water in the beaker. Stop heating and remove from the tripod stand once bubbles are observed in the water or when the water boils.
2. Add one spatula of copper (ll) sulphate into the hot water.
3. Stir the mixture until the copper(ll) sulphate dissolves before adding another spatula of copper(ll) sulphate.
4. Repeat Step 3 until no more copper(ll) sulphate can be dissolved
5. Filter the solution if there are any solid impurities.
6. Heat the copper(ll) sulphate in an evaporating dish.
7. Stop heating when about half the solvent has evaporated from the solution. Do not heat the solution to dryness. (If a crust form,stop heating and add a little water)
8. Pour the solution into a boiling tube and cool it in ice-cold water and measure the time taken for crystals to appear.
9. Collect the crystals and dry them on filter paper
10. Observe the crystals formed.

Step 6

Residue left after filtering the solution

Step 8

After a while of cooling (crystals are forming)

So there! The very awesome experiment.

Reflection: It was cool to see how crystallization was performed as this process is applied to daily life, to make sugar crystals that we eat. I think it is a tedious process though, to make sugar crystals.

End

#9 Entry- EXPERIMENTS!

Today we did 2 experiments. One on Chromatography and simple distillation.

Since it was a very simple process, Mr Foo did not show us a sample set-up.

Steps:
1. Take a strip of chromatography paper and use a ruler to draw a line about 1.5cm away from the end of.
2. Dip the capillary tube into green ink, and blot a little in the middle of the drawn line.
3. Repeat this process till you get a concentrated spot of food coloring.
4. Add distilled water into the test tube till you cover the circumference of the bottom of the tube.
5. Slowly insert the chromatography paper into the test tube, making sure that the paper does not touch the line.
6. Use a clothes peg to secure the paper. Meanwhile, wait for the distilled water to rise.
7. Measure the distance where the distilled water stopped. Draw a line. This line is called the solvent front, and is the maximum amount.
8. Rf= Distance travelled by spot / Distance travelled by solvent

Component	Distance moved by spot/cm	Distance moved by solvent/cm	Rf
Yellow	6	11.6	0.517
Blue	10	11.6	o.862

Simple Distillation:
Mr Foo demonstrated the simple distillation method with coke. It was really smelly!

Anyway, I learnt that simple distillation and fractional distillation are similar in some ways. Both of them have boiling, condensation and require heat energy. They are different in the sense that simple distillation does not require fractionating while fractional distillation has fractionating column.

They are used to separate solvent from a solution and the fractional distillation is to separate 2 miscible liquid.

Reflection: I learnt many new things today, and learnt way we have to study about this topic. It is essential to scientists, food manufacturers etc to determine the purity of a substance using chromatography, and also using simple distillation to obtain pure water.

Thats all for today!

#8 Entry- Separation Techniques

We covered Separation Techniques today, in preparation for tomorrow's practical.

First we did a recap on paper chromatography, and here are some things to note when carrying out the experiment.

• always use pencil to mark the line, not pen as pen contains ink 
• solvent front: where the ink stop moving, the ink will not go beyond this line
• mobile phase: solvent (moving)
• stationary phase: paper (not moving)
• make sure the ink doesn't touch the pencil line 
• solvent below pencil line so that the solutes would not be in contact with it
• ink does not dissolve well in water but dissolves well in ethanol

The Rf Value

(Source: http://usefulchem.wikispaces.com/JanuPExp001 )

Rf Value = Distance moved by substance/ Distance moved by the solvent

Conditions that affects the results:

• Pressure
• Temperature ( for example, if you heat up the solvent, solubility will increase and the spot will be higher, thus more solvent will dissolve. 

To cause a Rf difference: Change solvent / temperature

Simple Distillation

(Source: http://www.ied.edu.hk/apfslt/v8_issue1/tanks/tanks3.htm )

• Separate the solvent from a solution of so lute
• IMPORTANCE: Solvent is the main aim
• Distilled water: No ions at all, pure, however, if humans depend on distilled water, it is unhealthy since we need certain ion and compounds
• No evaporation

We were left with some question to do research on:

1. What is the purpose of the boiling stone
2. What does it mean by smooth boiling and/ or what happens if you do not have it?
3. What is the condenser for?
4. What is the thermometer for? 
5. Why is there are water inlet and water outlet? What purpose does their position serve?

1/2. What is the purpose of the boiling stone AND What does it mean by smooth boiling and/ or what happens if you do not have it?

• known as the boiling chips/ anti-bumping granules
• minute, unevenly shaped stones added to liquid so that they can boil easily
• fluids can boil easily without turning superheated
• without the, liquid heater in horizontal container might become superheater and 'bump' suddenly. discharging vapour occasionally
• reagents/ discharge may spill it it bumps
• made of absorbent matter eg alumina, calcium, carbonate, carbon, with non-reactive teflon which makes sure boiling chips offer effective nucleation spots

3. What is the condenser for?

• What water is boiled in a close container known as a boiler, vapour evaporating from the surface of the boiling water passes through a pipe leading from the boiler to a vessel, called a condenser

4. What is the thermometer for?

• Positioning is crucial: entire mercury bulb must be positioned below the bottom of the orifice leading to the condenser

5. Use of water inlet and outlet

• Cold water is used to condense the gas to become liquid. It should not switch places because water out is hotter and hot water rises due to convection. If the water outlet is put below, the condenser would not work because the whole set-up will heat up and hence it does not serve its purpose.

Reflection: Today I learnt why separation techniques are important as well as did research that increased my knowledge of this topic.

Next Lesson: Practical- Separation Techniques

#7 Entry- Summary of ECM, Separation Techniques

Today, we briefly summarised ECM and started a little on Separation Techniques.

Summary

Mixture of elements:

Which diagram shows the mixture of elements?

Ans: Z

Types of mixtures: 

• 2 elements
• 2 compounds
• 1 element, 1 compound

Compound must have fixed proportion of certain elements. A different proportion will result in a completely different compound. Eg H2O

Alloy:

• Mixtures of metals and other elements
• Stronger than normal metals (pure metals are malleable)
• eg bronze, stainless steel

Separation Techniques

Separation techniques are used to separate mixtures.

Types of techniques:

Filtration, distillation, chromatography and/or electricity, chemical reactions

Filtration: Used when one substance is soluble and the other is not soluble in water

Examples of Pure and Not Pure

Pure	Not Pure
Oxygen	Carbon Dioxide
Acid	Water

*pure: all elements on the Periodic Table

Why must substances be pure?

• Health hazards
• Food, medicine must be pure 
• Test out characteristics of certain elements: Properties such as melting point, boiling point, density
• Identification: Test to prove something, hence, have to separate first
• Production of useful substances
• There isn't 100% pure substances, at most, it can be 99.99999...% pure
• To determine the degree of purity: Mass Difference

How to determine if something is pure:

• Fix melting point, boiling point
• Chromatography: Separated into different components

Paper Chromatography:

• Separate mixtures of solutes with different solubility and degree of absorption
• More soluble: move further up
• Not so soluble: Stay at the same position
• Use a solvent medium/ porous or absorbent: paper/gel
• Dye/ Sugar (Sugar: Glucose/Fructose)

Process:

That's all for today!