questions you Keep Getting Wrong Flashcards
what colour does the solution change in the experiment of magnesium + copper sulphate
Blue —-) colourless
What happens to the copper at the end of the experiment with magnesium and copper sulphate?
Copper coats the magnesium and then sinks to the bottom
What is the colour change in the thermal decomposition of calcium carbonate and state the products
Colourless—-) cloudy
Calcium oxide + carbon dioxide
What is the colour change in the thermal decomposition of copper carbonate and state the products
Green —-) black
Copper oxide + carbon dioxide
What is the state symbol for when iron has rusted
(S) Hydrated iron (iii) oxide is a solid
What is the difference between when iron reacts with hydrochloric acid and when iron reacts with cold water
Slow fixing, test tube becomes slightly warm and turns a green solution
But no reaction with cold water
When calcium carbonate reacts with hydrochloric acid what is formed
Calcium carbonate + hydrochloric acid —-) calcium chloride + water + carbon dioxide
What are the chemical names for limestone, lime water and quick lime
Calcium carbonate is lime stone
Calcium hydroxide is lime water
Calcium oxide is quick lime
What colour is copper oxide
Black
What colour is litmus in neutral solutions
Purple
During metal extraction, which economic factors are considered?
Price of the reducing agent
Energy of fuel
What are two exceptions of covalent compounds that can be used in electrolysis
Ammonia
Hydrogen chloride
Give one property of carbon dioxide that makes it appropriate in fire extinguishers
More dense than oxygen
What happens when excess carbon dioxide is bubbled through lime water?
Solution turns colourless
(Remember that when normal amount of carbon dioxide is bubbled through limewater solution turns cloudy. This experiment is used to investigate respiration)
What is sacrificial protection
Process where more reactive metal prevents a less reactive metal from corroding
What is an allow, and why is aluminum alloy stringer than pure aluminum alloy
Alloy is a mixture of more than one elements, and contains a metal
Because alloy has different sized ATOMS which disrupt the regular lattice structure so IONS are not able to slide over each other
What is the anode rule and what is the cathode rule
Anode rule asks if the ion is a halide or not, and if it is, the halide will go to the anode and form hydrogen
Cathode rule is whether it is more reactive or less reactive than hydrogen, and less reactive element will go to the cathode
For oxidation half equation and for reduction half equation, what side does the electron go on
For oxidation, electron goes on the right side(because it is being lost and in chem u don’t show negative electrons)
For reduction, electron goes on the left side
Copper and nitric acid is in a molar ratio 1:4
0.05 mol Cu reacts with 0.4 mol nitric acid. Calculate the limiting reactant
Copper is limiting reactant
Go to ur exercise book to see the full reasoning and answer
