other questions Flashcards
what are the clues for a chemical change (6)
bubbles of gas form, change of colour, odour, precipitate, irreversible change, heat or light
what are the diatomic molecules
hydrogen, nitrogen, oxygen, chlorine, fluorine, bromine, iodine (H2, N2, O2, Cl2, F2, Br2, I2)
list common polyatomic ions
hydroxide (OH) , chlorate, carbonate (CO3), nitrate, phosphate, sulfate, bicarbonate (HCO3), ammonium(NH4)
what is the law of conservation of mass
during a chemical reaction, the total mass of the products must be equal to the total mass of the reactants.
law example
A= 50g + B=75 AB= 125g. A=50g AB=125g B=?
what is corrosion and how can it be prevented?
the breakdown of a metal resulting from reactions with chemicals in its environment. a simple way to prevent corrosion is to cover the metal with a rust-inhibiting paint, chrome, or plastic coating.
what are the properties of acids (7)
conducts electricity, reacts with metals and carbonates, neutralize bases, tastes sour, turns blue litmus paper red, pH lower than 7, dissolves in water
what are the properties of bases (5)
conducts electricity (forms ions), feels slippery, tastes bitter, turns red litmus paper blue, pH greater than 7
what does pH mean
power of hydrogen
What do the numbers from 0 to 14 mean in terms of measuring pH
it measures the amount of H+ ions in a solution. it can also detect if a substance is acidic, basic or neutral
How does red and blue litmus change when it comes in contact with an acid or a base?
light blue litmus paper turning red under acidic conditions and red litmus paper turning blue under basic or alkaline conditions
how are baking soda and Alka-Seltzer tablets similar
these substances are both basic and neutralize stomach acid
