Science: Chemical Change Flashcards
What are the types of chemical changes?
Combustion, thermal decomposition, oxidation, and neutralisation
What is combustion?
a chemical reaction in which a substance is heated in the presence of oxygen
What is thermal decomposition?
a process in which a substance breaks into two or more simpler substances upon heating
What is oxidation?
gain of oxygen. no heat is required for this chemical reaction.
What is neutralisation?
when an acid and a base react to form water and a salt
What are the properties of acids?
Acids have a sour taste.
Acids turn blue litmus paper red.
Acids dissolve in water to form solutions which
can conduct electricity.
Acids react with reactive metals to form a salt and
hydrogen gas.
What happens when acids react with metals?
salt and hydrogen gas
e.g. magnesium + sulfuric acid → magnesium sulfate + hydrogen
What happens when acids react with carbonates?
salt, water and carbon dioxide
e.g. zinc carbonate + sulfuric acid → zinc sulfate + water + carbon dioxide
Types of acids (to memorise)
Hydrochloric acid, nitric acid, sulfuric acid
Is salt an alkali, acid or neutral substance?
Salt is neutral
DONT SAY THAT THE SUBSTANCE FIZZED!!!!!! SAY THAT EFFERVESCENCE IS PRODUCED INSTEAD
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What happens when acids react with alkali?
salt and water during neutralisation
What is the chemical symbol (thingy) for hydrochloric acid, nitric acid, and sulfuric acid?
HCl is hydrochloric acid
HN3 is nitric acid
H2SO4 is sulfuric acid
Which are the diatomic substances (substances that cannot exist as one)
hydrogen (H), nitrogen (N), oxygen (O), fluorine (F), chlorine (Cl), bromine (Br), and iodine (I)
What is the test to identify hydrogen gas?
Insert a lighted splinter into (e.g. reaction test tube). The light splint will extinguish with a ‘pop’ sound.
