Topic 3 Quantitive Chemistry Flashcards
What is a mole?
A word used to describe the amount of substances (atoms, ions, molecules) in a mass of a chemical.
What is Avogrado’s constant?
The amount of particles that one mole of a substance always contains.
What always happens to mass in a chemical reaction?
It is conserved- no atoms are destroyed or created so the mr of the reactants and products is the same.
What is the usual cause of a mass change in a reaction?
A gas.
If the mass increases it’s a gas in the air.
If the mass decreases it’s probably because one of the products is a gas.
When do reactions stop?
When one product is used up- any other reactants are in excess to ensure that the other reactant is used up.
What is the reactant used up in a reaction called?
The limiting reactant.
What is the product formed directly proportional to?
The limiting reactant.
At room temperature what does one mole of any gas equal?
24dm^3
What is concentration?
The amount of substance in a certain volume of a solution.
What does the atom economy of a reaction tell you?
How much of the mass of the reactants is wasted when manufacturing a chemical and how much end up in the desired products.
The higher the atom economy…
The more environmentally friendly the process.
What are the advantages/ disadvantages of high atom economy?
Better profits and environment.
What are the disadvantages of low atom economy?
- Use up resources very quickly
- Make lots of waste
- Unsustainable if the raw materials are non renewable
- Expensive
- Non Profitable
Why are yields always less than 100%?
- Not all reactants make products
- There might be slide reactions
- You lose some product when you separate it from the reaction mixture.
