Groups Rates And Energy Changes Flashcards
What are group 0
Noble gases
Why are group 0 inert
They all have a full outer shell
What happens as you go down group 0
The b.p, m.p and density increase
What are the boiling points of group 0
Lower than room temp
What are some properties of noble gases
Colourless, very low b.p and m.p, Poor conductors of heat and electricity, all exists as single atoms because dont form bonds easily with other atoms
Uses of krypton
Photography lighting
Uses of argon
Added to the space above the wine in wine barrels
Uses of helium
Used in weather balloons and airships
Neon uses
Illuminated signs
What are group 1
Alkali metals
How many electrons do alkali metals have in their outer shell
1
What happens as you go down group 1
The reactivity increases
Why does the reactivity of group 1 increase as u go down it
As we move down the group, the outer electron is less attracted to the nucleus and easier to lose
Example of a reaction of an alkali metal with O2
4Li + O(2) — 2Li(2)O
Example of reaction of group 1 with chlorine
2Li + Cl(2) — 2LiCl
Example of reaction of group 1 metal with water
2Li + 2H(2)O — 2LiOH + H(2)
What are group 7
Halogens
What are halogens
Non metals
What happens as u go down group 7
Melting and boiling points increase
How many electrons do halogens have in their outer shell
7
What happens when group 7 react with other non metals
They form a covalent bond
What hapoens when group 7 react with metal atoms
Form an ionic compound
What happens to the group 7 atom when it reacts with a metal
The group 7 element gains one electron and forms a -1 ion
Definition for rate of reaction
The speed at which reactants are turned into products
How can you control rate of reaction
Altering the concentration of solutions and the size of the pieces of solid reactant
What is activation energy
The minimum amount of energy needed for a reaction to occur
What are enzymes
Large complex protein molecules
What does an enzyme have
Active site
What are substrates
The reactant moleucles
What is an exothermic reaction
Energy is released
Endothermic reaction
Energy is needed
What is a neutralisation reaction
Reaction between acid and base, exothermic
What is a displacement reaction
Reaction between mental and a compound of a less reactive metal or between a halogen and less reactive compound of a halogen
How to calculate rate of reaction
Amount of reactant used or amount of product formed / time
What are the 3 ways to measure rate of reaction
Precipitation, change in mass, the volume of gas given off - gas syringe
What can u use to measure how surface area affects rate
Marble chips and hydrochloric acid
What is a precipitate
An insoluble solid in water
What does a steeper gradient show
Faster rate of reaction
What increases rats of reaction
Increasing temp
What is collision theory
Particles must collide with enough energy to react
What does rate of reaction depend on
Collision frequency, energy transferred during collision
What 3 things increases rate of reaction
Increasing temp, increasing concentration/pressure, smaller surface area/smaller solid particles
Why does increasing temperature increase rate of reaction
Makes particles faster, more collisions also increases energy of collisions - more successful collisions
Why does increasing pressure or concentration increase ror
If solution is concentrated there are more particles, increasing pressure makes particles more crowded - more frequent collisons
Why does smalled surface area/smaller solid particles increase ror
Higher rate increases surface area : volume ratio, particles have more area to work on collision frequency
How do catalysts work
They decrease the activation energy
What do reaction profiles show
Energy levels of products and reactants
What do catalysts do
Increase ror but never chemically change or get used up
Mass of proton
1
Mass of neutron
1
Mass of electron
0.0005
Charge of proton
+1
Charge of neutron
0
Charge of electron
-1
Properties of alkali metals
Soft, low melting points
What colour and physical state is chlorine at room temp
Poisonous green gas
What colour and physical state is iodine at room temp
Dark grey crystalline solid which gives off a purple vapour when heated
What colour and physical state is bromine at room temp
Poisonous red-brown liquid which gives off an orange vapour at room temp
What happens to the physical properties of halogens as you go down the group
The melting point increases and the halogens get darker
What do halogens form when they react with other metals
Salts called metal halides
What do halogens form when they react with hydrogen
Hydrogen halides which are soluble (dissolve in water) to form acidic solutions
What happens to the reactivity when u go down group 7
Reactivity decreases
What happens in a halogen displacement reaction
The halogens gain electrons (reduction) and the halide ions lose electrons (oxidation)
What is bond breaking
Endothermic
What is bind making
Exothermic
