HARD
MYP:4-5
IMPORTANT
Earn 100

Some creams are called vanishing because they seem to disappear when rubbed on the skin. Suggest the type of oil and water combination that would give a vanishing cream emulsion with this property.

Important Questions on How Do We Use Matter?

MEDIUM
MYP:4-5
IMPORTANT
MYP By Concept 4&5 Chemistry>Chapter 2 - How Do We Use Matter?>SOME SUMMATIVE PROBLEMS TO TRY>Q 8
During their use perfumes often present a range of impressions. After a first fleeting scent, there can be a range of different lingering impressions. Make a scientifically supported judgement to explain how this is possible.
MEDIUM
MYP:4-5
IMPORTANT
MYP By Concept 4&5 Chemistry>Chapter 2 - How Do We Use Matter?>SOME SUMMATIVE PROBLEMS TO TRY>Q 9
At a party in a bucket of iced water(i.e.containing both liquid and solid phase of water) you notice that cans of a regular soda sink, but cans of diet soda float. In the morning when all the ice cubes have melted the regular Coca-Cola and regular Dr Pepper drinks both float along with the diet sodas. Interpret this information and make scientifically supported judgements.  
HARD
MYP:4-5
IMPORTANT
MYP By Concept 4&5 Chemistry>Chapter 2 - How Do We Use Matter?>SOME SUMMATIVE PROBLEMS TO TRY>Q 10
Describe how a separating funnel can be used to differentiate between liquids of different densities?
HARD
MYP:4-5
IMPORTANT
MYP By Concept 4&5 Chemistry>Chapter 2 - How Do We Use Matter?>SOME SUMMATIVE PROBLEMS TO TRY>Q 11
When clothes are washed, suggest why it is difficult to remove grease spots from clothing using pure water?
HARD
MYP:4-5
IMPORTANT
MYP By Concept 4&5 Chemistry>Chapter 2 - How Do We Use Matter?>SOME SUMMATIVE PROBLEMS TO TRY>Q 11
When clothes are washed, if the clothes spoiled with grease spots is treated with a spray on stain, the stain remover washing becomes more effective. Suggest the chemical a stain remover might be, and describe how it works.
MEDIUM
MYP:4-5
IMPORTANT
MYP By Concept 4&5 Chemistry>Chapter 2 - How Do We Use Matter?>SOME SUMMATIVE PROBLEMS TO TRY>Q 12
Why don't chemists simply add smaller quantities of the essential oil directly to the other ingredients?
HARD
MYP:4-5
IMPORTANT
MYP By Concept 4&5 Chemistry>Chapter 2 - How Do We Use Matter?>SOME SUMMATIVE PROBLEMS TO TRY>Q 13
Explain why the Rf values for any set of specific conditions used in chromatography are constant. 
HARD
MYP:4-5
IMPORTANT
MYP By Concept 4&5 Chemistry>Chapter 2 - How Do We Use Matter?>SOME SUMMATIVE PROBLEMS TO TRY>Q 14
In the French perfumery industry pomade is made by placing fresh lavender on highly purified blocks of animal fat in cool dark rooms. After a few days, the fat is dissolved using cool alcohol leaving the essential oils from the flowers behind. Explain how this separation process demonstrates the awareness of the physical properties of essential oils