(Topic 3) Quantitative Chemistry (CGP Book) Flashcards
What is the Avogadro constant?
6.02×10*23
What is a mole of a substance?
The amount of any substance that contains an Avogadro number of particles
What is the equation for moles?
Mass divided by Mr
What happens during a chemical reaction?
No atoms are destroyed and no atoms are created
This means that normal mass is lost or gained
What happens if mass increases in a reaction?
Probably means one of the reactants is a gas and all the products are solids, liquids or aqueous
What happens if mass decreases in a reaction?
Probably means one of the products is a gas and all the reactants are solids, liquids or aqueous
How can mass increase in a reaction?
For reaction, gas is floating around in air
It is there, but it is not contained in the reaction vessel, so you can cannot account for its mass
When gas reacts to form part of product , it becomes contained inside reaction vessel. This means that the total mass of stuff inside the reaction vessel increases.
How can mass decrease in a reaction?
Before reaction, all reactants are contained in the reaction vessel
If vessel is not enclosed, then the gas can escape from the reaction vessel as it is formed this means that it is no longer contained in the reaction vessel, so you can cannot account for mass it’s
What is a limiting reactant?
Reactant that gets completely used up in a reaction before the rest meaning the reaction stops
How much space does one mole of any gas occupy?
24dm*3
What is the rule for gas, that is at the same temperature and pressure, equal numbers of moles?
Any gas will occupy the same amount of volume
How does a solution become more concentrated?
More solute there is a given volume
What are the two equations for concentration?
Concentration = mass of solute / volume of solvent
Concentration = number of moles of solute / volume of solvent
What is a titration?
An experiment that lets you find the volumes needed for two solutions to react together completely
What is atom economy?
The atom economy of a reaction tells you how much of the mass of the reactants is wasted when manufacturing a chemical and how much ends up as useful products
