Reaction Rate + Atomic Structure Flashcards
What are the reactants?
The substances that react together
What are the products?
The substances formed at the end of the reaction
What needs to happen for a reaction to take place?
The reactants must collide with sufficient energy so they can chemically bond.
What is reaction rate?
The speed at which a reaction takes place
Order these chemical reactions in order of slow to fast reaction time:
Boiling an egg
Decomposition
Toasting bread
Mentos + coke reaction
Iron rusting
Decomposition
Iron rusting
Boiling an egg
Toasting bread
Mentos + coke reaction
Why would the chemical industry need to speed up a reaction?
To make more products in as short a time as possible in order to maximise profits.
Why would the chemical industry need to slow down a reaction?
If a reaction is too energetic they need to slow it down.
If it is not slowed down, then this can be dangerous.
What are the 4 ways of altering reaction rate?
- Increasing the temperature increases reaction rate
- Increasing the “surface area” increases reaction rate
- Adding a catalyst increases reaction rate
- Increasing concentration increases reaction rate
How can temperature cause an increase in reaction rate?
Temperature is related to kinetic energy. As things get hotter, their atoms move faster. This means that their is a higher chance for a successful collision.
How does concentration increase reaction rate?
It is because there are now more atoms/molecules in the same volume. This means that there is now a greater chance of a successful collision.
What is a catalyst?
A substance that speeds up a chemical reaction.
What are the characteristics of a catalyst?
Catalysts can be reused because it remains unchanged (after being used in a reaction).
They lower the temperature of a reaction.
What are one of the main cons of catalysts?
They are expensive.
eg: 20g of palladium = £642.80
eg: 20g of rhodium = £2141.60
How can we monitor how long a reaction takes?
We can:
- measure the time it takes for a gas to be produced
- measure how long it takes for the concentration to change
PLEASE REFER TO DIAGRAMS IN YOUR JOTTER RELATING TO THIS QUESTION, AND COMMIT THEM TO MEMORY.
Practise drawing apparatus for monitoring a reaction.
Do it closed-book. Rate by seeing how well you do.
What can we produce from monitoring a reaction?
We can produce a table and then a graph
What is the formula for counting average rate?
Average rate = Δquantity/Δtime
Imagine you have drawn a graph that produces a gas. The gas is collected and its volume was measured every minute. What will the height of the graph tell us?
The height tells us how much gas is produced
How do you know when the reaction has stopped on the graph?
The point where it becomes horizontal, it stops
What tells you on a graph how fast the reaction was?
The steeper the gradient, the faster the reaction.
How many elements are there on the periodic table?
118
What are different ways that the PT can be arranged?
Solids (105), liquids (2), and gases (11)
Metals (96) & Non-metals (22)
What’s the standard way of arranging the PT?
Periods and groups and the number of protons in the nucleus.
What are the named groups in the PT?
Group 1: The Alkali Metals
Group 2: The Alkaline Earth Metals
Between groups 2 & 3: Transition Metals
Group 7: The Halogens
Group 8: The Noble Gases
How are elements sorted in their groups?
Elements which have similar chemical properties are found in the same groups.
What do atoms all have?
A central nucleus and energy levels
What 2 sub-atomic particles are found in the nucleus of an atom?
Protons and Neutrons
Where is the 3rd particle of the atom found?
The electron is found orbiting the nucleus inside energy levels
What does every neutrally-charged element have the same number of?
Every elements has the same number of protons as electrons
What is the number of protons in an atom called?
The Atomic Number
What is the mass of a proton?
1 a.m.u
What is the charge of a proton?
1+
What is the mass of a neutron?
1 a.m.u
What is the charge of a neutron?
0
What is the overall charge of an atom?
The overall charge is 0. I.E: it is neutral
Where is most of an atoms mass located?
In the nucleus
How is the mass number calculated?
The number of protons + neutrons added together.
How can the number of neutrons be calculated?
Mass number - Atomic number
How is nuclide notation put together?
m
E
a
What are isotopes?
Atoms of the same element with a different number of neutrons
What can a spectrometer identify about an element?
How many isotopes there are
The mass number of each
The abundance of each
True or False? Most elements have two or more isotopes.
True
True or False? The electron arrangement of the first 20 elements can be written
True
How does surface area increase reaction rate?
We increase surface area by making the solid break up into smaller pieces, ie: we decrease particle size. By breaking up the solid we expose new surface. The greater the surface area, the higher chance of a successful collision.
What is the mass of an electron?
1/2000th a.m.u
