Exam (elaborations)
ELECTROCHEMISTRY A - LEVEL CHEMISTRY QUESTIONS AND ANSWERS WITH SOLUTIONS 2024
- Course
- Institution
ELECTROCHEMISTRY A - LEVEL CHEMISTRY QUESTIONS AND ANSWERS WITH SOLUTIONS 2024
[Show more]
Seller
Follow
Performance
Reviews received
Content preview
ELECTROCHEMISTRY A - LEVEL CHEMISTRY QUESTIONS AND ANSWERS WITH SOLUTIONS 2024 Why must a high resistance voltmeter used in electrochemical cells to measure the potential difference? - ANSWER The voltmeter needs to be of very high resistance to stop the current from flowing in the circuit. In this state it is possible to measure the maximum possible potential difference (E). The reactions will not be occurring because the high resistance voltmeter stops the current from flowing. Oxidising agent - ANSWER Accepts electrons and gets reduced. Reducing agent - ANSWER Donates electrons and becomes oxidized. Disproportionation - ANSWER A redox reaction in which the same species is both oxidized and reduced. Why do electrochemical cells require a salt bridge? - ANSWER The salt bridge allows ions to flow between the solutions to complete the circuit, keeping the balance of positive and negative ions in each half cell without them mixing together. The salt bridge is often a piece of filter paper or agar gel soaked in potassium nitrate which is will not react with either of the solutions in the half cells). What is electromotive force? - ANSWER There is a potential difference between the two electrodes. If there was a bulb in the circuit instead of a high resistance voltmeter a current would flow as because of the potential difference chemical energy is converted to electrical energy. The voltmeter takes measurements when there is zero -current which means the measurements is the maximum possible potential difference between the two half cells and this is called the e.m.f. Electrode potential depends on? - ANSWER 1. Nature of ions in the solution 2. Conc. of ions in the solution 3. Type of electrode 4. Temperature What happens if the oxidising agent > 1M - ANSWER Favours reduction, more positive E What happens if the oxidising agent < IM - ANSWER Favours oxidation, more negative E What happens if 2 gases are want to measured. - ANSWER They are bubbled through the solution so it it in contact with the electrode What happens if the current is allowed to flow between the two half cells - ANSWER If there was a bulb in the circuit instead of a high resistance voltmeter a current would flow as because of the potential difference chemical energy is converted to electrical energy. The reactions will then occur separately at each electrode. The voltage will fall to zero as the reactants are used up. What do electrochemical cells consist of? - ANSWER Two half -cells that have to be connected with a salt bridge and which have electrodes that can conduct electricity when connected by wires.The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Performance. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R270,04. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
64438 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now