nanoparticles and some quantitive chem

Question 1

what are nanoparticles

Answer 1

very very tiny particles which have a diameter between 1 nm and 100nm
they are particles which contain only a few hundred atoms

Question 2

properties of nanoparticles

Answer 2

high surface to volume ratio ( surface area/ volume) so would be an effective catalyst

Question 3

uses of nanoparticles

Answer 3

some can conduct electricity - can be used in computer chips

nanomedicine- tiny particles like fullerenes are absorbed more easily by the body than most particles

silver nanoparticles- antibacterial purposes, can be added to polymer fibres then used to make surgical masks, wound dressings

also used in cosmetics, used in sun creams as they protect skin from harmful UV rays and also give better skin coverage

Question 4

Why aren’t nanoparticles being used more

Answer 4

• its effects on health and the body are not fully understood yet
• some believe they might have a negative effect on human health, unsure on what the long term impacts on health will be, needs to be investigated properly
• because of this, products containing nanoparticles should be labelled in case people don’t want to use them

Question 5

properties of solids

Answer 5

• strong forces of attraction between particles
• particles close together in fixed positions
• particles dont move, solids have a fixed shape and volume
• particles vibrate when heated

Question 6

properties of liquids

Answer 6

• weak forces of attraction between particles
• definite volume but no fixed shape
• particles are constantly moving around with random motion
• expand slightly when heated

Question 7

properties of gases

Answer 7

• forces between particles are very weak
• no fixed shape or volume
• gases expand when heated

Question 8

what happens during melting

Answer 8

• using heat, the forces between the particles are broken, allowing them to move around

Question 9

what are some limitations of the simple particle models

Answer 9

• the model assumes that all particles are solid spheres and this is not the case
• the model shows that there are no forces between the particles in a solid

Question 10

What is atom economy

Answer 10

A measure of the amount of starting materials that end up of useful product

Question 11

advantages of atom economy

Answer 11

• by minimising the production of unwanted products, we save money
• also increase sustainability

Question 12

atom economy equation

Answer 12

relative formula mass of desired product/ sum of relative formula masses of all reactants x 100

Question 13

do big numbers count in atom economy

Answer 13

yes

Question 14

why can atom economy not be higher than 100%

Answer 14

because it would mean that were creating atoms which isnt possible