Chemistry - Ch. 5 (Yr 10) Flashcards
What is the ‘law of mass of conservation’ ?
Bonds break and reform in chemical reactions but no atoms are destroyed nor created, therefore, the mass remains the same.
What does the rearranging of atoms do in terms of mass and products?
The mass stays the same and the products are different from the reactants.
What does a ‘catalyst’ do?
It speeds up reactions.
The number of atoms in the reactants must be ……. to the amount in the products. (Fill in the gap)
Equal
What are the subscripts and their symbols?
S = solid
g= gas
l= liquid
aq = Aqueous
What does ‘aqueous’ (aq) mean?
Soluble in water
How do you balance an equation?
Count the amount of each element, then add numbers ONLY in front of the elements to make them equal on each side.
What is the general equation of a synthesis reaction?
A+B —> AB
The combining/making.
What is the general equation of a decomposition reaction?
AB —> A+B
Breaking down
What is synthesis?
The forming of compounds by combining simpler elements and substances.
What is decomposition?
The breaking down of compounds into their simpler substances.
What is the general equation for a neutralisation reaction?
Neutralisation:
acid (pH 1-6) + base (pH 8-14) —> water (pH 7) + salt
What ions do acids contain?
Hydrogen ions (H+)
What ions do bases contain?
Hydroxide ions (OH-)
The reactants ‘Acid + metal oxide’ create a product of?
Salt + water
The reactants ‘Acid + metal’ create a product of?
Salt + Hydrogen