Category 1
The ionic formula for Al3+ and O2-
Al2O3
Why is the solid called "insoluble"?
Because it does not dissolve in water.
Are all nitrates soluble or insoluble?
Soluble.
Using the solubility rules, determine if CuCO3 is soluble or insoluble
Insoluble
most carbonates excluding sodium carbonate, potassium carbonate and ammonium carbonate are insoluble
What would you observe if a precipitate forms?
The solution becomes cloudy or a solid appears.
What is a precipitate?
An insoluble solid that forms when two aqueous solutions are mixed.
How can you tell a precipitation reaction has occurred?
A solid forms and the solution becomes cloudy or a coloured solid appears.
A beaker contains 50.0 g of silver nitrate solution. Another contains 30.0 g of sodium chloride solution. They are mixed and a white precipitate forms.
What is the total mass after the reaction?
80g
What colour is silver chloride?
White
What colour is lead iodide?
Bright Yellow
Which ion is responsible for forming the precipitate? what do the remaining ions form & what are they?
AgNO₃ + NaCl
Ag⁺ and Cl⁻, spectator ions (soluble substance), Na⁺ and NO₃
What are the two types of substances that must usually be mixed to produce a precipitation reaction?
Two aqueous (dissolved) ionic solutions.
Are most chlorides soluble or insoluble?
Soluble
Identify if a precipitate will form when NaOH + Ni(NO3)2 reacts.
Yes precipitate - Ni(OH)2
If no precipitate forms, what does this tell you?
The products are soluble and remain dissolved.
Complete the reaction:
AgNO₃(aq) + NaCl(aq) → ______
AgCl(s) + NaNO₃(aq)
A chemist wants to remove every Pb²⁺ ion from a solution.
Why should they avoid adding too little potassium iodide?
Not all the lead ions will react, so some Pb²⁺ ions will remain in solution.
Name one chloride that is insoluble.
Silver chloride (AgCl) or Lead(II) chloride (PbCl₂).
Engineers need to remove lead ions (Pb²⁺) from contaminated water.
Would potassium iodide or sodium nitrate work better?
Explain.
Potassium iodide because PbI₂ is insoluble and forms a precipitate.
Why is observing colour important during practical work?
It helps identify whether a reaction has occurred and what precipitate may have formed.
Which solution should you add to remove calcium ions?
A) Sodium carbonate
B) Sodium nitrate
Why?
Sodium carbonate because CaCO₃ is insoluble. Because nitrates are all soluble
Why must chemical equations be balanced?
Because atoms cannot be created or destroyed, so the same number of each atom must appear on both sides of the equation.
A chemist wants ALL of the silver ions removed from a solution.
Should they add:
Excess sodium chloride, so every silver ion has chloride ions available to react and form AgCl.
100 mL of AgNO₃ solution reacts completely with 100 mL of NaCl solution.
A student accidentally adds 150 mL of NaCl.
What remains in the final solution?
All silver ions have reacted. Excess sodium ions and chloride ions remain dissolved along with sodium nitrate
To remove a stain faster, Jenny applies more stain remover. Which of the methods of increasing the rate of reaction is Jenny using?
Increasing concentration of reactants