My Cards 2

Question 1

What is shape memory metals

Answer 1

It can remember it’s original shape if broken or deformed

Question 2

What is Thermosoftening polymers

Answer 2

WEAK FORCES
Individual tangled chains of polymers held by weak intermolecular forces and slide over each other.

They don’t have cross links between chains so the forces between the chains are easy to overcome and easy to melt. You can melt and remould as many times as you like

Question 3

What is thermosetting polymers

Answer 3

STRONG FORCES
These have strong intermolecular forces between polymer chains called crosslinks which hold the chains firmly together. It doesn’t soften when heated. They are strong hard and rigid

Question 4

What is the advantage of nanotechnology

Answer 4

Get into the body easier in delivering drugs or suncream.

Very very small.

Don’t know what long term impact as it is very recent.

Question 5

What are isotopes

Answer 5

Different version of the same element

Question 6

How do u work out a relative formula mass

Answer 6

Multiply the amount of atoms you have by the elements weight

Question 7

What is Ar

Answer 7

Relative atomic mass

Question 8

What is Mr

Answer 8

Relative mass formula

Question 9

To find the percentage of and atoms in the Ar you..

Answer 9

divide the Ar of that atom and divide it by the Ar of the full equation then multiply by 100

Question 10

How do u work out empirical formula

Answer 10

List the elements in their experimental masses. Then divide my the atomic mass of each element. Turn the numbers you get into a ratio by multiplying and/or dividing them by well chosen numbers(e.g 0.8 multiplied to 8). Get the number into its simplest form and then it tells you the empirical forumla. Answer e.g = Fe203 (empirical formual is the 2 and the 3)

Question 11

How do u calculate percentage of mass of an element in a compound

Answer 11

Ar X number or atoms of that element
—————————- X100
Mr of the whole compound

Question 12

What is yield

Answer 12

The useful product given from a reaction

Question 13

How do you work out the percentage of yield?

Answer 13

Actual yield (grams)
-------------
Predicted yield(grams)

Question 14

Can you ever get 100% of yield ?

Answer 14

No! Some product or reactant will get lost along the way

Question 15

What is the reason for the maximum amount of yield produced?

Answer 15

Because it was a reversible reaction. This means the products of a reaction can react themselves to produce original reactants

(E.g ammonium chloride ammonia+hydrogen chloride

—–>

Question 16

Why do we use chromatography

Answer 16

To separate out substances

Question 17

How do You produce a chromatography experiment

Answer 17

Place food colour either mixture
Or one dye out on chromatography paper but draw a pencil line to put spots on. Hang it over a beaker with solvent in making sure the pencil line is above the solvent . The solvent seeps up that paper taking dyes with it and makes different dyes form in different places on the paper.

Question 18

What are advantages of machines analysing unknown substances

Answer 18

Very sensitive
Very fast
Very accurate

Question 19

How is gas chromatography

Taken place?

Answer 19

A sample enters the oven. Lower down the line a gas is entered to carry the substance around. The substances travel through the tube at different speeds so they separate out.

Question 20

What does the rate of reaction depend on

Answer 20

Temperature
Concentration
Catalyst
Surface area of solids

Question 21

How do you measure the rate of reaction

Answer 21

Time

Question 22

What are the 3 ways to measure

Rate of reaction

Answer 22

Precipitation (when product clouds in solution)

Change in mass (usually gas given off)

Volume of gas given off (using gas syringe)

Question 23

More collisions….

Answer 23

Increase the rate of reaction. This is because higher temperature increases collisions as particles move quicker. Higher concentration (or pressure) increases collisions as there is more particles to collide with. Larger surface area increase collisions so there is more area to work on.

Question 24

What are the 3 broken down reasons for collision theory

Answer 24

1) higher temperature
2) higher concentration or pressure
3) larger surface area

Question 25

What does a catalyst do

Answer 25

Speeds up a reaction without be changed or used up

Question 26

In industrial reactions what do catalyst’s do?

Answer 26

Reduce costs.