Chemistry 3.4 Flashcards
Chemical formula of Hydroxide
OH -
Chemical formula of Nitrate
NO3 -
Chemical formula of Carbonate
CO3 2-
Chemical formula of Sulphate
SO4 2-
Chemical formula of Ammonium
NH4 +
What does -ate mean?
Tells you that oxygen is present.
What do acids form when added to water?
They form positively charged Hydrogen ions (H +)
What do alkalis form when added to water?
They form negative hydroxide ions (OH –)
metal + acid –>
salt + hydrogen
metal oxide + acid –>
salt + water
metal hydroxide + acid –>
salt + water
carbonate + acid –>
salt + water + carbon dioxide
Ammonia + acid –>
Ammonium salt
Formula of Sulphuric acid
H2 SO4
Formula of Nitric acid
HNO3
Formula of hydrochloric acid
HCl
Formula of phosphoric acid
H3 PO4
When do diatomic atoms apply?
When the element is on its own in a symbol equation
Are Nitrates soluble?
Yes
Are halides soluble?
Most EXCEPT lead (II) and sliver halides
What are halides?
Elements in Group 7.
Are sulfates soluble?
Most EXCEPT lead (II), barium and calcium sulfates.
What is the charge on lead (Pb)?
2+
Which group’s salts are always soluble?
Group 1.
Are Carbonates soluble?
No, however GROUP 1 CARBONATES ARE SOLUBLE.
Are Hydroxides soluble?
No, however GROUP 1 HYDROXIDES ARE SOLUBLE.
Are Ammonium salts soluble?
Yes, except ammonium oxides.
What is an alkali?
Releases Hydroxide (OH-) ions.
What are metal oxides?
Bases.
What are non-metal oxides?
Acids.
What is an observation of magnesium oxide/combustion of magnesium?
Bright white light or white solid formed.
Why is the acid heated up in a reaction?
To speed up the reaction.
What is an observation of sulphur dioxide?
Blue flame.
Charge on Zinc Iron
2+
Charge on Silver ion
+
Charge on Copper
2+
Charge on Lead
2+
Describe how to find out if an unknown element is a metal or non-metal.
Combust with oxygen.
Dissolve the oxide in water.
Determine the pH of the solution with an indicator.
Metal = Alkali solution
Non metal dioxides = Acid solution
Methyl Orange Indicator colour change
Red in acid
Orange in neutral.
Yellow in alkalis
Steps to prepare lead (II) sulphate
Mix 2 soluble salts together while stirring
Filter to remove precipitate from mixture
Wash filtrate with distilled water to remove traces of other solutions
Leave in an oven to dry
Abundance of Nitrogen in air.
78%
Abundance of Oxygen in air.
21%
Abundance of Argon in air.
0.9%
Abundance of Carbon Dioxide in air.
0.04%
What is an acid?
A H+ donor.
What is a base?
A H+ acceptor
What is an alkali?
An OH- donor.
What should you be careful with when using polyatomic ions in chemical formulae?
You have to use brackets.
Observations of a carbonate + acid reaction.
Carbonate disappears- Is used up in reaction.
Fizzing- Gas (carbon dioxide) is produced.
Steps for Insoluble Base method.
1- Heat acid (speeds up reaction)
2- While stirring, keep adding base until no more will dissolve. (Guarantees that all the acid has been used up/excess base)
3- Filter out the excess base
4 - Transfer to evaporating basin
5 - Heat until crystals form on glass rod
6 - Allow solution to cool for a few days
7 - Filter out crystals
8 - Dry crystals using filter paper
When would you use the Titration method?
When the base you are using is soluble, the insoluble base method wouldn’t work because you wouldn’t be able to filter out the excess.
Crystallisation - You use this no matter which method you used to make the salt (but only for soluble salts)
1 - Transfer solution to an evaporating basin. Heat the salt solution and stir with a glass rod until crystals start to form (causes solution to become saturated).
2- Allow solution to cool for a few days (reduces solubility of solution).
3- Filter out the crystals.
4- Pat the crystals dry with filter paper.
Making an insoluble salt by precipitation method
1- Mix two solutions together in a beaker. (Dissolve in water if they are solid)
2- Filter to collect the solid precipitate.
3- Wash with distilled water.
4- Pat the solid dry with filter paper.
What type of solutions do metal oxides form when dissolved in water?
Alkaline
What type of solutions do non-metal dioxides form when dissolved in water?
Acid
Observation of carbon combusting
Orange glow, universal indicator in water turns from green to orange
Observation of iron combusting
Burns very quickly with orange flame, universal indicator in water turns from green to dark green
What are all metal oxides and hydroxides?
Bases
Reasons for why the % of oxygen in air experiment result does not match.
Leaks in equipment letting more air (and therefore oxygen) into the experiment.
Metal wasn’t heated enough or for long enough for all the oxygen to react
What do all bases react with acid to form?
salt and water
Why is Ammonia (NH3) a base?
Can accept H+ to form ammonium ion
What is an alkaline solution?
Alkali has dissolved and donated OH- into the water causing a pH greater than 7
Observation of Hydrogen combusting
Squeaky pop
What is produced when hydrogen is combusted?
Water