Summary
Summary Study / Revision notes - Topic 2 Experimental tecniques - Chemistry CIE IGCSE (A* student)
- Course
- Institution
Study / Revision notes - Topic 11 Air and water - Chemistry CIE IGCSE (A* student)
[Show more]
Seller
Follow
luciaromeroojeda
Content preview
LUCÍA ROMERO2. EXPERIMENTAL TECHNIQUES
DEFINITIONS
1. Element: a substance that cannot be decomposed into anything simpler by chemical means, a substance made up of atoms all of which
have the same atomic number (same number of protons).
2. Compound: a substance which contains 2 or more elements chemically combined and fixed proportions by mass.
3. Mixture: contains 2 or more substances (elements or compounds) that are not chemically combined. Mixtures do not have a chemical
formula.
4. Solution: a liquid which contains a substance or substances dissolved in it
5. Solvent: a pure liquid in which a substance is dissolved
6. Solute: a dissolved substance in a solution.
2.1 MEASURMENT
Time
Units → seconds / minutes
Measured using... a stopclock or a stopwatch
Temperature
Units → degrees Celsius
Measured using... a thermometer (digital for a more precise measurement) (traditional for a more accurate measurement)
Mass
Units → grams / kilograms (1kg = 1000g)
Measured using... a weighing balance or top pan balance or digital balance
Volume
Units → cm3/dm3/ml/l
( 1cm3 = 1ml 1dm3 = 1l 1000cm3 = 1dm3 = 1l )
LIQUIDS
• For approximate volumes where accuracy is not an important factor → measuring cylinders are used
- to measure volume quickly
- These are graduated (have a scale so can be used to measure) and are available in 25 cm 3, 50 cm3, 100 cm3 and 250 cm3
• Volumetric pipettes → the most accurate way of measuring a fixed volume of liquid, usually 10 cm 3 or 25 cm3
- also, to TRANSFER and deliver a liquid
• Burettes → the most accurate way of measuring a variable volume of liquid up to 50 cm3 (e.g. in a titration) - only used to DELIVER
liquids
GASES
• A gas syringe is usually the apparatus used
2.2 PURITY
What are pure substances?
Substances that...
1. Have no particles of another substance mixed with them
2. Melt and boil to temperatures unique to them
3. Melt sharply at their melting point
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 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 these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller luciaromeroojeda. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $6.12. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
82265 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now