Conrad Course material 10025 14 years and over 10025 Manual De Usuario

Fig. 61: Experimental set-up: splitting water up. The solar radiation is additionally enhanced by a 
mirror. 
 
Fig. 62: Basic circuit diagram for splitting water up shows a solar module and the electrodes. 
 
Experimental set-up: a dish with water and some sodium bicarbonate or common salt Plain water 
conducts current very poorly. If sodium bicarbonate is added to the water, oxygen and hydrogen come 
about through the electrical splitting up. If common salt is used, oxygen and chlorine gas come about. 
You can use two wires as electrodes, ca. 10 cm long, the ends of which were stripped about 2 cm.  
 
a) 

Arrange the bare ends of the wires vertically in the dish beneath the surface of the liquid at the 

maximum distance from one another and secure them with clothes pegs to the dish. The solar direct 
current is conducted into the liquid through the two wires as electrodes. (By means of electrolysis, 
reaction products come about at the electrodes from the substances contained in the liquid.) 
b) 

Connect the wire electrodes to the solar module. When beams of sunlight shine on the solar 

module, you can see that little bubbles rise at the two wire ends in the liquid – at the negative pole 
about twice as much as at the positive pole.  
c) 

An additional LED is series indicates the flow of current. Since the current is very slight, you 

can perceive the weak shining of the LED more or less. 
 
Fig. 63: In order to additionally show the flow of current, an LED is inserted in the circuit. The 
additional electrolytic capacitor C1 is not obligatory for the functioning of the circuit, but it stabilises the 
functioning.