Topic #4: Chemical Changes Flashcards Preview

Chemistry > Topic #4: Chemical Changes > Flashcards

Flashcards in Topic #4: Chemical Changes Deck (18)
Loading flashcards...
1
Q

What happens when metals react with oxygen?

A

A metal oxide is produced

This is a oxidation reaction because it gains oxygen

2
Q

State the series of reactivity.

A
Potassium
Sodium
Lithium
Calcium
-------------- react with cold water
Magnesium
Aluminium
-CARBON-
Zinc
Iron
------------------ react with steam
Tin
Lead
--------------reaction boundary for dilute acid
-HYDROGEN-
Copper
Silver
-------------- reaction boundary for oxygen
Gold
Platinum
------------------ No reaction
3
Q

What will displace a metal from its compound?

A

A more reactive metal

4
Q

How are metals found?

A
Unreactive metals (eg. gold) are found in the earth
Most metals require extraction from ores via chemicla processes
5
Q

How are metals extracted from ores?

A

The oxide is reduced (loses oxygen) by bioleaching

ONLY IF IT IS ECONOMICALLY VIABLE

6
Q

What is phytomining?

A

Planting a plant over an ore and letting the roots absorb ions, then burn it to get the ions off

7
Q

What is OIL RIG in terms of electrons?

A

Oxidation
Is
Loss

Reduction
Is
Gain

8
Q

List the acid reactions

A

Acid + metal = salt and hydrogen
Acid + metal (hydr)oxide = salt and water
Acid + metal carbonate = salt and water and carbon dioxide
Acid oxide + base = salt and water

9
Q

What happens in neutralisation?

A

Acids react with alkalis/bases to form salts and water, or carbonates to add carbon dioxide

10
Q

How are soluble salts made by acids?

A

By adding solid insoluble substances

11
Q

What do all acids have in aqueous solutions?

A

H+ ions

12
Q

What do all alkalis have in aqueous solutions?

A

OH- ions

13
Q

How ionised are different strength acids?

A
Strong acids (eg nitric, sulphuric, hydrochloric) are fully ionised
Weak acids (eg citric, ethanoic) are only partially ionised
14
Q

What factor does the H ion concentration decrease by per pH?

A

Ten

15
Q

What happens at the electrodes during electrolysis?

A

Ions are discharged

16
Q

What are cations, cathodes, anions and anodes?

A

Anode- positive, attracts cations (negative charge)

Cathode- negative, attracts anions (positive charge)

17
Q

When are ions replaced and where?

A

Cathode: If they are less reactive than hydrogen (oxidation)
Anode: If they are less reactive than hydroxide (reduction)

18
Q

What is the name of the electrolyte substance?

A

Cryolite