Transcript Reaction with Metals

Reaction with Metals - general
• Many metals react with acids to form a salt and
hydrogen gas.
• The general word equation is:
metal
+
acid

a salt
+ hydrogen
• The salt will depend upon the metal and the acid used.
•Hydrochloric acid gives metal chlorides
•Sulphuric acid gives metal sulphates
•Nitric acid gives metal nitrates
•So, for example
magnesium + hydrochloric  magnesium +
acid
chloride
hydrogen
Evidence of Reaction
Some of these reactions show
bubbles being produced.
These are bubbles of hydrogen
gas. This proves that a
reaction is taking place
because a new substance is
forming.
Oxygen in the air
hydrogen
How do we test for hydrogen?
Mg + acid
Lighted
spill
Activity
• Use the general equation to finish of the word
equations below
metal
+
magnesium +
iron
calcium
Zinc +
acid

a salt
sulphuric
acid

magnesium
sulphate
+ nitric acid 
+
sulphuric 
acid
hydrochloric 
acid
+ hydrogen
+
hydrogen
iron nitrate
+ hydrogen
calcium
sulphate
+ hydrogen
zinc
chloride
+
hydrogen
React with Metals – Metal Reactivity
•
Which metal fits the description
silver;
potassium; iron
1. Explodes in acid
potassium
2. Bubbles slowly in warm acid
3. Doesn’t react
silver
iron
Decreasing activity
• We can use the activity series of metals
to predict how vigorously (if at all) a metal
will react.
• The more reactive the metal, the more
vigorous the reaction.
• The least reactive metals do not react at
all.
Potassium
sodium
calcium
magnesium
aluminium
zinc
Iron
Lead
(Hydrogen)
copper
silver
gold
Formula of salts
• Chemists often use formula equations to show not just
what atoms are present but also how many.
• To do this we need to understand what the numbers in a
formula represent. Here are some examples.
Name of Salt
Formula
Contains
sodium chloride
NaCl
one Na
one Cl
magnesium chloride
MgCl2
one Mg
two Cl
potassium nitrate
KNO3
one K
one N
three O
potassium sulphate
K2SO4
two K
one S
four O
calcium nitrate
Ca(NO3)2
one Ca
two N
six O
Activity
• How many of each type of atom does the formula of the
salt represent?
Name of Salt
Formula
Contains
calcium chloride
CaCl2
one Ca
two
Cl
sodium sulphate
Na2SO4
two Na
one
S
four
O
magnesium sulphate MgSO4
one Mg
one
S
four
O
magnesium nitrate
Mg(NO3)2
one Mg
two
N
six
O
calcium sulphate
CaSO4
one Ca
one
S
four
O
Formula Equations:
• Step 1: Write down the word equation.
• Step 2: Replace words with the chemical formula . (You
will be given or need to look up the formula at this stage.)
• Step 3: Check that there are equal numbers of each type
of atom on both sides of the equation. If not, then balance
the equation by using more than one.
• E.g. The reaction of magnesium with hydrochloric acid
magnesium + hydrochloric  magnesium + hydrogen
acid
chloride
Mg
+
HCl

MgCl2
+
H2
Neither H nor Cl balance.Need 2 HCl
Mg
+
2HCl

MgCl2
+
H2
Activity
• Can you finish off the equations below:
– Step 1:
Write down the word equation.
– Step 2:
Replace words with the
chemical formula.
– Step 3:
Balance the type of atom on both sides.
sulphuric  magnesium +
acid
sulphate
+
H2SO4

MgSO4
+
Already balances; No change
hydrogen
sulphuric  potassium
acid
sulphate
H2SO4

K2SO4
Need 2 K on both sides
+
hydrogen
+
H2

+
H2
magnesium +
Mg
potassium +
K
+
2K
+
H2SO4
K2SO4
H2
Metals with Hydrochloric Acid
magnesium
Mg
+
+
copper
Cu
+
+
aluminium
2
Al
calcium
Ca
hydrochloric
acid

magnesium
chloride
+
hydrogen
2 HCl

MgCl2
+
H2
hydrochloric
acid

No reaction
2 HCl

-
hydrochloric
acid

+
+
+
+
6
HCl
hydrochloric
acid
2
HCl
 2
-
aluminium
chloride
+
hydrogen
AlCl3
+
3
H2

calcium
chloride
+
hydrogen

CaCl2
+
H2
Metals with sulphuric and nitric Acid
zinc
+
sulphuric
acid

zinc
sulphate
+
hydrogen
Zn
+
H2SO4

ZnSO4
+
H2
magnesium + nitric
Mg
+ 2
iron
2 Fe
calcium
Ca
+
+

HNO3
+ nitric
+
acid  magnesium +
nitrate
acid 
6 HNO3
sulphuric
acid
H2SO4
Mg(NO3)2
iron nitrate
 2 Fe(NO3)3


calcium
sulphate
CaSO4
+

hydrogen
H2
+
+
+
+
hydrogen
3 H2
hydrogen
H2

Metal oxides and acids
 a salt + water
Metal oxide + acid
• Most metal oxides are not
soluble.
• i.e. They are bases but not
alkalis. This means they are
often slower and may need
heating to make them react
Copper
oxide
+
sulphuric
acid
copper
sulphate
+

water
Acid
Oxide
Metal oxides and acids
 a salt + water
Metal oxide + acid
zinc oxide
+
sulphuric
acid

zinc
sulphate
+
water
ZnO
+
H2SO4

ZnSO4
+
H2O
sodium
chloride
+
water
2NaCl
+
H2O
sodium
oxide
+ hydrochloric 
acid
Na2O
+
2HCl
iron oxide
+
nitric acid
Fe2O3
+
3HNO3

 iron nitrate +
water

3H2O
Fe(NO3)3
+
Metal carbonates and acids
Metal carbonate + acid
 a salt + water + carbon dioxide
• When metal carbonates react with acids
they fizz giving off carbon dioxide gas.
• Most metal carbonates are not very
soluble and so reactions may be slow.
calcium
carbonate
+
hydrochloric 
acid
calcium
chloride
+
water
+
carbon
dioxide
Metal carbonates and acids
Metal carbonate + acid
 a salt + water + carbon dioxide
zinc
+ sulphuric 
zinc
carbonate
acid
sulphate
ZnCO3
+
H2SO4

ZnSO4
+ water +
+
H2O
+
carbon
dioxide
CO2
sodium + hydrochloric  sodium + water +
carbonate
acid
chloride
carbon
dioxide

CO2
Na2CO3
+
nickel
+
carbonate
NiCO3
+
2HCl
nitric acid
2HNO3


2NaCl
nickel
nitrate
Ni(NO3)2
+
H2O
+
+ water +
+
H2O
+
carbon
dioxide
CO2
2. Which of these is NOT a typical
property of metals?
A.
B.
C.
D.
conduct
strong
dense
brittle
3. What is the symbol for Gold?
A.
B.
C.
D.
Go
Au
Ag
au
4. Which of the following elements is
not a metal?
A.
B.
C.
D.
copper
lead
lithium
neon
Which of these is a salt?
A) Sodium carbonate
B) Sodium chloride
C) Sodium hydroxide
D) Sodium
Which of these do all acids contain?
A) Hydrogen
B) Sulphur
C) Oxygen
D) Nitrogen
Which of these salts might be formed
from nitric acid?
A)
B)
C)
D)
Potassium chloride
Sodium nitride
Aluminium sulphate
Calcium nitrate
Which of these metals might not react
with hot dilute acid?
A)
B)
C)
D)
Sodium
Calcium
Silver
Iron
Which of these substances would not
neutralise an acid?
A)
B)
C)
D)
Silver nitrate
Sodium carbonate
Calcium oxide
Magnesium hydroxide
What number must replace X to balance the
equation?
Fe(OH)3 + X HCl 
A)1
B)2
C)3
D)4
3H2O
+ FeCl3
What number must replace X to balance the
equation?
CaCO3 + X H2SO4  H2O + CaSO4 + CO2
A)
B)
C)
D)
1
2
3
4