<p>Electrolysis of water is the decomposition of water into <a data-lesson="occurrence-preparation-and-compounds-of-oxygen" data-subject="chemistry" data-tutorial="metals-metalloids-nonmetals" href="https://app.ulearngo.com/chemistry/metals-metalloids-nonmetals/occurrence-preparation-and-compounds-of-oxygen">oxygen</a> and hydrogen gas due to an electric current being passed through the water. The reaction has a standard potential of −1.23 V, meaning it ideally requires a <a data-lesson="potential-difference-equilibrium-and-concentration" data-subject="chemistry" data-tutorial="electrochemical-reactions" href="https://app.ulearngo.com/chemistry/electrochemical-reactions/potential-difference-equilibrium-and-concentration">potential difference</a> of 1.23 volts to split water.</p>
<div class="ns-school-emp">
<h2>Experiment: The Electrolysis of Water</h2>
<div class="ns-school-defn">
<section class="activity">
<h3>Aim</h3>
<p>To investigate the <a data-lesson="elements" data-subject="chemistry" data-tutorial="classification-of-matter" href="https://app.ulearngo.com/chemistry/classification-of-matter/elements">elements</a> that make up water.</p>
</section>
<section class="activity">
<h3>Apparatus</h3>
<ul>
<li>
<p>water</p>
</li>
<li>
<p>two pencils sharpened at both ends</p>
</li>
<li>
<p>9 volt battery</p>
</li>
<li>
<p>connecting wire</p>
</li>
<li>
<p>tape</p>
</li>
<li>
<p>table <a data-lesson="acid-base-reactions-continued-2" data-subject="chemistry" data-tutorial="acid-base-redox-reactions" href="https://app.ulearngo.com/chemistry/acid-base-redox-reactions/acid-base-reactions-continued-2">salt</a> or <a data-lesson="redox-reactions" data-subject="chemistry" data-tutorial="reactions-in-aqueous-solution" href="https://app.ulearngo.com/chemistry/reactions-in-aqueous-solution/redox-reactions">sodium</a> sulfate</p>
</li>
</ul>
<img alt="8b668ff7a9e0f47f929b11dc7157cb02.png" src="https://data.ulearngo.com/assets/22bb194f-e646-462b-a1df-eb7f535b22f1"/></section>
<section class="activity">
<h3>Method</h3>
<p>Set up the apparatus as shown above. Observe what happens.</p>
</section>
<section class="activity">
<h3>Results</h3>
<p>You should observe bubbles forming at the tips of the pencils. Oxygen gas is formed at the positive <a data-lesson="dissociation-in-water" data-subject="chemistry" data-tutorial="reactions-in-aqueous-solution" href="https://app.ulearngo.com/chemistry/reactions-in-aqueous-solution/dissociation-in-water">side</a> and hydrogen at the negative side.</p>
</section>
</div>
</div>

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Electrolysis of Water Experiment

Chemistry generally explores the substances of which matter is composed, the investigation of their properties and reactions, and the use of such reactions to form new substances. 

Chemistry

Explore the essential ideas in chemistry, including the scientific method, laboratory skills and safety, states of matter, measurement uncertainty, models of the atom, electronic configurations, and more.


Electrolysis of Water Experiment

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