Groups in the periodic table SC17 + Rate of reaction SC18 + Exo/endo thermic reaction SC19

Question 1

What is in group 1 on periodic table?

Answer 1

Alkali metals

Question 2

What are the properties of alkali metals?

Answer 2

all malleable and conduct electricity
relatively low boiling points, soft, easy to cut, very reactive and readily form compunds with non-metals

Question 3

what is true about alkali metals in air?

Answer 3

easily oxidised and burn brightly in air

Question 4

What is the order or alkali metals with reactivity increasing (start with least reactive)

Answer 4

Lithium
Sodium
Potassium
Rubidium
Ceasium
Francium

Question 5

What can be observed of alkali metals?

Answer 5

• atom size inceases
• outermost electron gets further away from the positive nucleus
• electrostatic force between nucleus
• outermost electron gets weaker
• therefore electron is lost easier

Question 6

how do alkali metals react with water?

Answer 6

• react vigorously lower down the list (explosive)
• form hydrogen + metal hydroxide
• higher up: fizz, move, gass given off

Question 7

how do alkaline metals react with chlorine gas?

Answer 7

• react more vigorously going down
• metal + chlorine = metal chlorine (white solid)

Question 8

What is group 7 composed of in the periodic table (what is the group name commonly called)?

Answer 8

Hallogens

Question 9

What are the hallogens in group 7? give their appearances too (decrease reactivity - start at highest)

Answer 9

Florine (pale yellow)
Chlorine (pale green gas)
Bromine (Orange/brown liquid)
Iodine (grey solid)
Astitine (black solid)

Question 10

What are the properties of hallogens?

Answer 10

• made up of two atoms
• Simple molecular structure
• Melting + boiling points increase going down
• Reactivity decreases going down

Question 11

what do hallogens form when making an ionic bond with metal?

Answer 11

metal halide

Question 12

what happens with halogens in displacement reactions?

Answer 12

more reactive ones always displace less reactive ones

Question 13

what are the properties of nobel gasses?

Answer 13

• colourless gas
• Non flamable
• Low boiling point
• Dont conduct heat/electricty
• Dont react (inert)
• Boiling point inc as going down group

Question 14

What is the common name for group 0?

Answer 14

Nobel gasses

Question 15

What are the nobel gases?

Answer 15

Helium
neon
argon
krypton
Xenon

Question 16

why are nobel gases non reactive?

Answer 16

full outer shells - cannot take on any more electrons

Question 17

What factors effect the rate of reaction?

Answer 17

concentration increase
temperature increase
catalyst added
large surface are: volume ratio
pressure increase

Question 18

what are 2 ways rate of reaction can be measured?

Answer 18

quantity reactants / time
or
quantity of products/ time

Question 19

how does concentration increase rate of reaction?

Answer 19

increases the amount of particles in a given volume, increases the frequency of collisions between particles leading to more successful collisions

Question 20

how does temperature increase rate of reaction?

Answer 20

increases the temeprature, increases kinetic energy of particles - increases the frequency of collisions between particles leading to more successful collisions

Question 21

how does a catalyst increase rate of reaction?

Answer 21

spees up ROR by lowering activation energy by providing an alternative energy pathway, mass of catalyst remains constant so isnt used up

Question 22

how does large surface area : volume ratio increase ROR?

Answer 22

large surface area: volume ratio, increases the frequency of collisions between particles leading to more successful collisions

Question 23

How does pressure increase effect ROR?

Answer 23

increases pressure decreases volume and moves the particles closer together, increases the frequency of collisions between particles leading to more successful collisions

Question 24

how will ROR differ between granules and block of reactant?

Answer 24

granules increase ROR as they are smaller and hence increase surface area : volume ratio

Question 25

What is the equation used when comparing ROR - what is used to measure CO2? why is CO2 measured?

Answer 25

HCl + CaCO3-> CaCl2 + CO2+ H2O
use gas syringe
CO2 is measured becase more C02 given = quicker ROR

Question 26

how to calculate rate of reaction at time X?

Answer 26

draw a straight line at an angle through the point - connect in a triangle - use equation:
difference in y axis / difference in x axis = gradient

Question 27

What is are properties exothermic reaction?

feels … to touch, gives/recieves energy?

Answer 27

• gives off energy to surroundings
• feels hot to touch
• thermometer reading goes up during reaction
• Bonds formed > bonds broken

Question 28

what are the properties of an endothermic reaction?

Answer 28

• takes in energy from surroundings
• feels cold to touch
• thermometer reading goes down during reaction
• bonds formed < bonds broken

Question 29

what does a reaction graph look like for an exothermic reaction?

Answer 29

• activation energy needed is small
• Entholopy change in reaction is negative
• products end lower than reactants (less energy)

Question 30

what does a reaction graph look like for an endothermic reaction?

Answer 30

• lots of activation energy required
• entholopy change is positive
• products finish with more energy than reactants

Question 31

what is activation energy?

Answer 31

minimum energy required to start a reaction