Home page > Meetings > 2010-11 Medvode
Science Workshop: The black worms
Slovensko |
English |
Laboratorijski pripomočki -kalupi za izdelavo tablete (odrezane škatlice za film, plastenke, jogurtovi lončki …) -čaša -kovinski pladenj -lesena trska -tehtnica |
Laboratory instruments -models to make a tablet (cut off boxes for a film, plastic bottles, yoghurt cups ...)
-a beaker (a glass or plastic cup) -a metal tray -a wood splinter -scales |
Reagenti (kemikalije) -soda bikarbona, NaHCO3(s) -sladkor -etanol, C2H5OH(aq) -mivka
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Reagents (chemicals) -bicarbonate of soda, -sugar -ethanol, -very fine sand |
Zaščitna oprema
-halja, -zaščitna očala |
Protective equipment
-an overall -protective glasses (blinkers) |
Potek dela: The course of work:
Slovensko |
English |
· Pripravimo zmes 100 g sladkorja in 12 g sode bikarbone.
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- We prepare the mixture of 100 g of sugar and 12 g of bicarbonate of soda.
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· Zmesi dodamo toliko etanola, da dobimo lepljivo maso, ki ne teče. |
- We add the mixture as much of ethanol to get sticky mass which doesn’t flow. |
· Naredimo tableto tako da zmes napolnimo v kalup. · Kalup odstranimo in tableto posušimo.
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- We make a tablet so that we fill up the model with the mixture. - We remove the model and dry up the tablet. |
· V posodo, ki je odporna proti ognju natresemo mivko. · Mivko namočimo z etanolom. · Etanol naj se vpije v mivko. Na mivki ne sme biti lužic. · Od količine mivke je odvisen čas gorenja, od tega pa velikost kače. · Posodo z mivko položimo na ognjevarno podlago. · Suho tableto položimo na mivko, prepojeno z etanolom in z leseno trsko prižgemo etanol.
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- We shake down the fine sand into the fire- resistant dish. - We soak the fine sand with ethanol. - The fine sand must absorb the ethanol. There mustn’t be any puddles on the fine sand. - The time of burning depends on the amount of the fine sand and depending on all this is the size of a snake. - We put the dish with the fine sand on the fire-resistant base. We put the dry tablet on the fine sand, soaked with ethanol and then we light the ethanol with a wood splinter. |
Razlaga: Explanation:
Slovensko |
English |
· Iz tablete v plamenih gorečega etanola prične rasti črna kača. · Zaradi visoke temperature sladkor v tableti ogleni, soda bikarbona pa razpada na natrijev karbonat, vodno paro in ogljikov dioksid. · Plin napihuje oglje v lahko porozno maso, ki spominja na kače.
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- From the tablet in flames of the burning ethanol a black snake starts arising. - Because of high temperature the sugar in the tablet is carbonizing, meanwhile the bicarbonate of soda is decaying into sodium carbonate, water vapour and carbon dioxide. - Gas is blowing up the charcoal into light porous mass, looking like snakes. |
Nevarnosti: Attention:
Slovensko |
English |
· Pazimo, da se ne opečemo · Vse gorljive snovi in etanol umaknemo na varno razdaljo, predno prižgemo etanol v mivki · Nikoli ne dolivamo alkohola med eksperimentom. · Nikoli ne dolivamo alkohola na vročo mivko. · Nosimo zaščitna očala in haljo.
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- We must be careful that we don’t get burned. - We remove all the flammable substances to a safe distance before we light the ethanol in the fine sand. - We never add alcohol by pouring during the experiment. - We never add alcohol on the hot fine sand. -We wear protective glasses and an overall.
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