Science fair! your input sought: measuring electricity, measuring gas weight and vol.

[Long Island Bob]

Some of you may remember that about a year ago my son and I started goofing around with electrolysis experiments. Basically we started with a hoax you tube video which involved water burning after batteries had been put in it for a few hours and fooled around until with it until we made it work.

(To make it work we dropped some standard AA batteries in a plastic bottle half-filled with salt water AND CAPPED IT. We could immediately see the gas bubbles forming out of the water, and within a few hours when we uncapped the bottle and held a lit match over it we got a nice short, slightly scary WOOF of flame.)

Anyway this morning at breakfast my son (9 years old 4th grade) asked if we could start doing those types of experiments again. I said that we cold and suggested that we continue goofing around until we came up with one or more really good experiment to try for the winter science fair.

To get some ideas
- here’s a 1-minute video where a high school class uses hydrogen to launch a “rocket” (soda bottle)
http://www.youtube.com/watch?v=-dav51pKTW8&feature=related
- here’s a 7-minute video (the relevant parts running from 4:14 to 5:30) where a high school kid performed electrolysis at home. His experiment is VERY similar to the ones my son and I did.
http://www.youtube.com/watch?v=5HWlx--tQbA&feature=related
- Here’s a 2-minute video of a college professor doing the same thing on a roof using a commercial solar panel.
http://www.youtube.com/user/SOLARH2


For instance we might try using distilled water vs. distilled water with dissolved table salt vs. ordinary sea water and see which creates the most hydrogen.

We might try the same experiment indoors (room temperature vs. outdoors fall/winter temperature) and see which creates more hydrogen.

Anyway I’ve noticed that in several of the videos the experimenters measured the number of volts and amps used to drive the hydrolysis.

Well I remember that ohms law is amps = volts/ohms and that Watts = Volts x Amps.

What I DON’T know is which of those (watts volts or amps) is most meaningful in this context.

Presumably, to show that two sets of experiments (e.g. indoor and outdoor) are identical we should measure the electricity used to drive each process and ensure the measurements are the same in each case.


So with that extended indtroduction, my questions are:
- Which measurement(s) (volts, amps wattts)should we use (feel free to explain why)
- Should I use this opportunity to teach my son any important electricity lessons, which ones and why?
- To measure the amount of hydrogen and oxygen created we are planning to capture it in balloons weight the balloons and then weigh the combination. (we'll also measure the amount of water at the start and at the conclusion). Are there any OTHER methods we should use?
- What else should we keep in mind?
- What else might we want to try?

[Long Island Bob]

related:

Here's a site that sells a 6 Volt Solar Panel (generates electricty to power the experiments). the site does not say how many amps or watts. Price: $21.40 + SH
http://www.denverdiscountmart.com/OUTDOOR/ELECTRONICS-AND-INSTRUMENTS/38405.html


For $23 + S&H I can get this puppy:
http://www.batteryjunction.com/12vsopabachs.html
It prduces 12 volts, with 2 Watts maximum power and "Working current" (whatever that is) of 150mA max.

For $25 plus $27 S& H I can get a biggie with lots of numbers that are . . . .well bigger.
Working Voltage：18V
Working Current：0.3A
Open Circuit Voltage：21V
Short Circuit Current：0.38A
SLA battery Voltage：12v

http://cgi.ebay.com/5W-18V-Solar-Panel-Car-Boat-RV-Battery-Charger-new_W0QQitemZ180306902463QQcmdZViewItem

so ummm . . (scratches head) well ummm . . . . your guidance wold be appreciated.

[texan_rep]

While this experiment isn't the explosive type, it is still an interesting one.

Place a small candle (votive or tea candle) in a bowl, and surround the candle with baking soda.

Light the candle.

Slowly pour vinegar into the baking soda (don't pour it on the candle)

Describe what happens and why...

[Long Island Bob]

While this experiment isn't the explosive type, it is still an interesting one.

Place a small candle (votive or tea candle) in a bowl, and surround the candle with baking soda.

Light the candle.

Slowly pour vinegar into the baking soda (don't pour it on the candle)

Describe what happens and why...

neat-o

We've used that fizzy reaction many times in other ways and
I'm going to guess that the C02 pushes away all the nearby oxygen and the candle goes out.




Meanwhile, as to electricity, I guess I should measure both (since the videos did.)

I remember thinking in the 6th grade that if you took a 100cc syringe of water and squirted the water out gently that would be "100 cc's of amps" but "very few volts" while if you took the same 100cc's of water in the same syringe and squirted it out as hard as you coud that would be "100 ccs of amps but a LOT of volts.)

anyway, the knowledageable folks who made the videos seemed to find it important to measure both so we shall measure both.


What about the solar panels? Which one is better? Which one should I buy?

[RickRhetoric]

Place a small candle (votive or tea candle) in a bowl, and surround the candle with baking soda.

Light the candle.

Slowly pour vinegar into the baking soda (don't pour it on the candle)

Describe what happens and why...

Okay, I'm doing it as I sit at the monitor and follow your instructions. I've lit the candle and I'm pouring vinegar into the baking soda. OMG! It's starting to

[texan_rep]

neat-o

We've used that fizzy reaction many times in other ways and
I'm going to guess that the C02 pushes away all the nearby oxygen and the candle goes out.

correct...that's why you put it in a bowl, so the CO2 can collect instead of flow away.





I remember thinking in the 6th grade that if you took a 100cc syringe of water and squirted the water out gently that would be "100 cc's of amps" but "very few volts" while if you took the same 100cc's of water in the same syringe and squirted it out as hard as you coud that would be "100 ccs of amps but a LOT of volts.)


The analogy isn't bad, but it's not really how it works. What you would really have is 100ccs of charge in both cases, and the amps in each case would be different. Current (amps) is charge/second.

In fact, that's the only difference between a AAA cell and a D cell. Both have the same voltage (1.5 volts)...but one is a little bitty syringe and the other is a bigger syringe.

[Greyclouds]

Just as an addition over and above what you are doing, ALWAYS ALWAYS ALWAYS make a control to your experiment!

For the example you gave above, measure the partial pressures of hydrogen and oxygen that come out of a regular bottle of water with no batteries in addition to the bottle of water that you added the batteries to.

[Long Island Bob]

Just as an addition over and above what you are doing, ALWAYS ALWAYS ALWAYS make a control to your experiment!

For the example you gave above, measure the partial pressures of hydrogen and oxygen that come out of a regular bottle of water with no batteries in addition to the bottle of water that you added the batteries to.

Hmm sounds good.


since we'll be capturing the hydrogen and oxygen in balloons we'll have to put a balloon over a bottle of water (with no electricity added) and use that as a control.

[Jíbaro]

Electricity isn't my specialty.Aerodynamics is.Buy a small flying model airplane and try the following:1 - Fly the model as is.

2 - Tape sand paper on top of the wing and try to fly it.

3 - Tape sand paper instead under the wing and try to fly it.The model should fly in cases 1 and 3, and have trouble flying in case 2.

[brouski]

Okay, I'm doing it as I sit at the monitor and follow your instructions. I've lit the candle and I'm pouring vinegar into the baking soda. OMG! It's starting to
:))

[orbitaldecay]

Not a scientist, but I enjoy (some) these videos and experiments:
http://amasci.com/amateur/videos.html
http://amasci.com/unew.html

[Long Island Bob]

Well the first night's experiments didn't go as planned.

We took four 0.5l bottles and filled them with 0.3l of salt water.
Next we labelled four balloons "0," "2," "4," and "6."
We dropped zero AA batteries into the first bottle, 2 AA batteries into the next, 4 into the next and 6 into the final one, and capped each bottle with its respective balloon.

As observed in the past, tiny bubbles immedidately began to rise from the negative terminal of each battery as the electricty changed the water from H20 liquid to H2 and O2 gas. The more batteries, the more quickly this happened.

However it appears that it takes a LOT of pressue to inflate a balloon more than a tiny amount. The balloons expanded to about 2 inches in diameter (they are 12 inches when fully inflated) the gasses started leaking out the (not very strong) seal between the balloon and bottle neck.





Next step we will repeat the experiment after stretching the balloons by inflating and then deflating them repeatedly. We will use tape to create a stronger seal and we might consider using a larger bottle (1 liter or 2 liters) with corresponding increases in the amount of salt water and batteries.

Either way, once we have found a method to capture and measure the gasses we are creating we will move on to whatever step PJ suggests (like using sea water and solare panels)

[Long Island Bob]

Anyway our first steps are all about goofing around until we can find a way to
- capture and measure or
- capture and compare the amount of gasses we create.

we know we can create the gasses and we know we can set them on fire.

[texan_rep]

Bob...the best way to handle that kind of experiment requires a little dexterity and something to hold the bottles.

Instead of using a balloon, you need some sort of rack that will hold the bottle off the ground while upside down. To keep the water from flowing out, the neck of the (inverted) bottle needs to be underwater.

In this configuration, the gases will rise to the top (bottom) of the bottle, displacing the water, which will exit out the neck.

In a science class, you could use a test tube with a one-hole stopper, and a flexible tube leading from the stopper to the (inverted) water-filled bottle.

A balloon is an ingenious idea, but as you have already discovered, a balloon adheres to Hooke's Law (spring force). Relaxing the balloons by inflating them prior to use will help, but can introduce error because the balloons will probably not be relaxed to the same degree.

[texan_rep]

This is a different experiment, but it shows the principle of water displacement...

[Long Island Bob]

Hmm I might have to dream up some two-bottle contraption.

If the second bottle is filled (or nearly filled) with liquid then, as gas is created, the gas will rise to the local highpoint and pressure will force the waterline downward (especailly if we leave somewhere for the water to go. We can simply use a ruler to compare the orginal waterline to the new water line to measure how much gas has been created.

I guess it's time to set up the old fish tank.
I wonder if it is tall enough.


It MAY not even be necessary for us to measure the amount of gasses we create.

Creating combustible gasses from seawater (especially if we use solar cells instead of batteries) would do pretty well in a science fair as is.

But I spoonfed him the experiment a year ago. For it to be HIS work he has to add to it in some significant way. His addition may or may not require that we be able to measure the results.

[Long Island Bob]

This is a different experiment, but it shows the principle of water displacement...


Interesting.

Of course the second test tube would have to be completely underwater to begin with, right?

[texan_rep]

intersting. Of course the second test tube would have to be completely underwater to begin with, right?

No...just needs to have the neck submerged. Try it in the sink..fill a bottle underwater, then lift it out of the water, keeping the neck submerged. You should be able to get the bottle completely out of the water (or close to it) without the water coming out.

[texan_rep]

Here's an idea, Bob...

1. Put water in the sink.
2. Put batteries in the first bottle.
3. Fill the bottle and QUICKLY put the bottle neck-down in the sink. If you can get it to stand while propped up against the side, great...otherwise, you'll have to hold it.
4. Let the batteries discharge.
5. Mark the level of gas on the bottle.
6. Empty the bottle and fill to the mark.
7. Measure that amount of water. That's your gas amount.
8. Repeat for other batteries.

[Long Island Bob]

Here's an idea, Bob...

1. Put water in the sink.
2. Put batteries in the first bottle.
3. Fill the bottle and QUICKLY put the bottle neck-down in the sink. If you can get it to stand while propped up against the side, great...otherwise, you'll have to hold it.
4. Let the batteries discharge.
5. Mark the level of gas on the bottle.
6. Empty the bottle and fill to the mark.
7. Measure that amount of water. That's your gas amount.
8. Repeat for other batteries.

Thanks.
Yes I think I'll do that.

Only I don't mind spending some money to buy lab equipment, so long as it is durable enough to last 8 years or so. It would be NEAT if PJ winds up with a small science lab in our basement.

Of course once we (you and I) find a way to measure the amount of gas created it will be PJ's job to come up with different experiments to see what method creates the most gas. (or at anyrate vary the experiment enough that it is his own.)




We are using half-liter bottles now. I'd like to find out what it takes to create an entire half-liter of gas.

Here's a 1-minute video of a HS science class who took a two-liter soda bottle filled with hydrogen and turned it into a rocket!!!!
http://www.youtube.com/watch?v=-dav51pKTW8&feature=related





On the way to school this morning PJ :angel: (4th grade, 9 years-old) told me he can solve the energy crisis and save the planet by showing the world how to create combustible fuel out of sea water and solar power. He said if he wins the Nobel Prize for this he'll share the money with me. Gotta love it!!

[texan_rep]

We are using half-liter bottles now. I'd like to find out what it takes to create an entire half-liter of gas.


Well, with the experiment as you currently have it (2, 4, 6, 8 batteries), plot number of batteries vs. amount of gas and you should be able to estimate from the graph.

[Long Island Bob]

http://forums.hannity.com/attachment.php?attachmentid=83091&d=1227618627
working so far so well.

the first of many "thank yous" are now due.

thanks

[texan_rep]

You're welcome...my pleasure. Let us know how everything comes out.

[Long Island Bob]

The inverted bottle method worked, but with limited success.
I suspect the inverted bottle is slowly leaking water out (leaving a vacuum or near vacuum.) Perhaps if we submerge or nearly submerge the spring water bottle we will get better results.

Anyway, here was attmept #2 step by step.

METHODS:
- Daddy (that's I) went out and bought a stand and some clamps.

- Then much like in the illustration, PJ and Daddy filled a spring water bottle with tap water, inverted it and used the stand and clamp to hold it in place with the bottle neck submerged in a bowl of tap water.

- We took a flask , filled it with salt water and six AA batteries and sealed it firmly except for a rubber tube which ran in the bowl, under water and up into the spring water bottle.

- We kept the remnants of our "sealed with a balloon" on hand for comaprison.

- Early this morning we resealed the inverted bottle (to do so we removed the bottle neck from the water, but kept it inverted so no gas heavier than air could escape.

- We took the inverted bottle and two of the balloon bottles outside. One at a time daddy opened them and PJ quickly held the lit end of a 12" lighter over the neck.

OBSERVATIONS AND RESULTS:
- Lots and lots of bubbles were created in the flask and the saltwater level dropped a tiny bit (about 10cc's).

- In about six hours time the entire 50 cc spring water bottle had no more water in it (this although the fluid level in the flask dropped only about 10 ccs.)

- Upon taking them outside and adding fire to the proximity the two balloon bottles each made somewhat loud and somewhat scary "WOOF" sound.

- The inverted bottle made a tiny and disatisfying "pip" sound.

- This was the case even though the inverted bottle contained no water and no batteries (presumably 50 cc's of newly created gas) while the ballon bottles were more than half full with salt water and batteries (and thus contained no more than 25 ccs of newly created gas.)

CONCLUSIONS:
None.

I suspect that an inverted bottle if filled with water and clamped with its neck submerged in a bowl of water will slowly drain leaving behind a vacuum.

I suspect that the gases we are creating are easily compressed and thus only a small portion of them were successfuly forced through the latex tube and into the invetrted bottle.


FURTHER STUDY:
I am now using the same clamp and stand to hang an inverted, water-filled bottle with its neck submerged in the same water-filled bowl to see if the water in the bottle really does slowly leak out of the bottle (leaving behind a vacuum.)

I plan to repeat the experiment using a very wide water-filled hose and making other changes in an attempt to capture more newly-created gasses in the spring water bottle.





Comments will be appreciated

[Long Island Bob]

Once Daddy and PJ get our tools and method squared away it is up to PJ to choose the next step(s) and turn this into a science fair experiment.

I believe he will choose something involving solar panels and seawater.
I plan to insist that he try at least two side-by-side experiments (e.g using one solar panel vs using three solar panels) in order that the final experiment be 100% his own.

[texan_rep]

:think:

If you have smaller bottles (or test tubes) those might be better...

Submerge the bottle farther into the water (been thinking...narrow neck, relatively large volume...may need to be submerged a little farther to prevent "leakage"...)

[Long Island Bob]

:think:

If you have smaller bottles (or test tubes) those might be better...

Submerge the bottle farther into the water (been thinking...narrow neck, relatively large volume...may need to be submerged a little farther to prevent "leakage"...)


so far our new bottle (with no tube and attached to no flask) isn't "leaking" much.

Perhaps we just mishandled the first bottle.

[ThinkingMan]

If you are still seeking advice for measuring the electrical properties of your experiment, I can be of help.

Your questions:
Which measurement(s) (volts, amps wattts)should we use (feel free to explain why)
- Should I use this opportunity to teach my son any important electricity lessons, which ones and why?

The electricity lesson: Whenever you apply a voltage across a substance that contains electrons that can move (in your case the electrolyte), the amount of electrons that will move depend on how much voltage you apply, and how difficult it is for the electrons to move in the substance. This is ohms law.

Voltage is measured with a voltmeter. The amount of electrons that are moving (current) is measured with an ammeter (an "amp meter"), and the difficulty of electron movement is measured with an ohmmeter (a resistance meter).

The amount of gas created depends on the current. This can be measured by putting an ammeter in line with any wire. Think of the ammeter as a piece of wire itself. The ammeter should not be "seen" by the circuit, even though it is right in it. Think of it as a water meter. The water meter does not affect the flow of water into your house, but it measures it.

It would be instructive to measure how much gas is collected based on the amount of current you measure (keep the voltage constant).

The currents may be small. The scale of the meter should be adjusted for this.

Note that there will be some heat generated. Some of the energy applied by the power supply (battery, etc...) is wasted as heat - typical of any system.

Let us know if you need more help.

[Long Island Bob]

If you are still seeking advice for measuring the electrical properties of your experiment, I can be of help.

Your questions:
Which measurement(s) (volts, amps wattts)should we use (feel free to explain why)
- Should I use this opportunity to teach my son any important electricity lessons, which ones and why?

The electricity lesson: Whenever you apply a voltage across a substance that contains electrons that can move (in your case the electrolyte), the amount of electrons that will move depend on how much voltage you apply, and how difficult it is for the electrons to move in the substance. This is ohms law.

Voltage is measured with a voltmeter. The amount of electrons that are moving (current) is measured with an ammeter (an "amp meter"), and the difficulty of electron movement is measured with an ohmmeter (a resistance meter).

The amount of gas created depends on the current. This can be measured by putting an ammeter in line with any wire. Think of the ammeter as a piece of wire itself. The ammeter should not be "seen" by the circuit, even though it is right in it. Think of it as a water meter. The water meter does not affect the flow of water into your house, but it measures it.

It would be instructive to measure how much gas is collected based on the amount of current you measure (keep the voltage constant).

The currents may be small. The scale of the meter should be adjusted for this.

Note that there will be some heat generated. Some of the energy applied by the power supply (battery, etc...) is wasted as heat - typical of any system.

Let us know if you need more help.

Thank you that is helpful.


FWIW we are repeating the initial experiment.

Along the way
we placed a spring water bottle (filled with tap water) neck down partialy submerged in a bowl of tap water. After 48 hours virtually none of the water had "leaked" out of the springwater bottle.

Whatever caused our disappointing wimpish little "pip" the first time does not appear to be related to the using an inverted spring water bottle to collect the gasses. We probaly mishandled the collection bottle.

[Long Island Bob]

This is a different experiment, but it shows the principle of water displacement...

PJ (and I ) have been tinkering with this for the past few months and he seems to have it working.

Here's an update:

1.)
PJ is now using ordinairy seawater instead of distilled water with a maximum concentration of table salt.

2.)
When PJ ignites his final results, it (they) sometimes creates a nice exciting "WHOOSH," and sometimes creates a whimpering little "poof," but either way, combustible gases (presumably hydrogen or a mix of hydrogen and oxygen) ARE being created. SUCCESS

3.)
PJ had been conducting the experiment by dropping 6-10 1.5 volt AA batteries directly in the flask.
Now the flask stopper has two small holes in it (I drilled them.) PJ stripped some wires inserted them through the holes and sealed the holes with hot glue.


4.)
He then attached the wires to two 6-volt lantern batteries wired in a series (he has done enough experiments wiht batteries to know that hooking them up in a series creates more volts than hooking themup in an array.)


5.)
Using wires and 2 6-volt batteries in a series intially created a LOT more bubbles than the old method (dropping 6-10 AA batteries directly into the water.)

PJ was so excited he squealed and started wondering if he'd win the Nobel prize for putting an end to both the energy crisis and global warming.

6.)
Within 5-10 minutes however the "positive" wire had corroded into pieces and the bubbles stopped forming.


7.)
I have now ordered some zinc and copper electrodes (basically 24 very flat popisicle sticks made of copper and 24 more made of zinc.)

8.)
A 12-volt solar panel (designed for charging RV batteries) is on order and should arrive soon.

9.)
I have (just) started making him read about atoms and molecules 2X a week in the hope that he will be able to discuss the results in his own words not by memorizing things I teach him.

[Long Island Bob]

got it working.

completed the experiment.

Yes it is possible to obtain combustible fuel (hdyrogen) from seawater using either batteries or solarpower.

Then I assigned PJ several age appropriate books and videos on chemistry.

He completed the display board, presented it to his class yesterday. the class loved it.


science fair is early next week
Looks good.