C10 - Chemical Analysis

Question 1

What is meant by Purity?

Answer 1

• A substance made of one substance, either element or compound
• Changes states at fixed temperature
• Fixed boiling point

Question 2

What are fixed points?

Answer 2

Melting/Boiling Point of an Element/Compound

Question 3

What is a Mixture

Answer 3

• A Substance made of multiple substances
• Fixed Points vary on its composition
• Doesnt have a fixed point, it changed states on different temperatures

Question 4

What is a Formulation?

Answer 4

Complex mixture designed to be useful

Question 5

What is a Physical Process

Answer 5

• Don’t involve chemical reactions, no new substances are made
• Separation Techniques: Chromatography, Filteration, Distillation are Physical Processes

Question 6

Chromotography

Answer 6

• Separated mixtures (ink) based on different Solubilities
• Pure mixtures would dissolve into one substance (one dot)
• Impurities would consider of many substances (many dots)

Question 7

Stationary Phase - Chromatography

Answer 7

Paper, because it doesn’t move

Question 8

Mobile Phase - Chromatography

Answer 8

Solvent, because it moves upwards

Question 9

Attraction - Chromatography

Answer 9

• Chemical closer to stationary phase (pencil mark) strongly attracted
• Chemicals further are weakly attracted

Question 10

Rf values - Chromatography

Answer 10

Distance Moved by Dot / Distance Moved by Solvent

Question 11

Testingfor Hydrogen

Answer 11

Burning Match creates Pop sound when meets test tube, Hydrogen presence

Question 12

Testing for Oxygen

Answer 12

Glowing Match relights when meets test tube, Oxygen presence

Question 13

Testing for Carbon Dioxide

Answer 13

Use Limewater which turns cloudy when reacted to test tube, Carbon Dioxide presence

Question 14

Testing for Chlorine

Answer 14

Insert damp litmus paper into test tube, Chlorine is present if paper is bleached/white