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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.
hydrogen+magnesium chloride
hydrochloricacid
+magnesium
•Hydrochloric acid gives Hydrochloric acid gives metal chloridesmetal chlorides•Sulphuric acid gives Sulphuric acid gives metal sulphatesmetal sulphates•Nitric acid gives Nitric acid gives metal nitratesmetal nitrates
•So, for example
Mg + acid
hydrogenLighted
spill
Oxygen in the air
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.
How do we test for hydrogen?
Zinc + hydrochloric + acid
• Use the general equation to finish of the word equations below
metal + acid a salt + hydrogen
iron + nitric acid +
calcium + sulphuric acid
+
iron nitrate
calcium sulphate
zinc chloride
hydrogen
hydrogen
hydrogen
magnesium + sulphuric acid
+magnesium sulphate
hydrogen
Activity
React with Metals – Metal Reactivity
• 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.
• Which metal fits the description silver; potassium; iron
1. Explodes in acid
2. Bubbles slowly in warm acid
3. Doesn’t react
potassium
iron
silver
PotassiumsodiumcalciummagnesiumaluminiumzincIronLead(Hydrogen)(Hydrogen)coppersilvergold
Decreasing activity
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.
calcium nitrate
potassium sulphate
potassium nitrate
magnesium chloride
sodium chloride
Name of Salt
six Otwo None CaCa(NO3)2
four Oone Stwo KK2SO4
three Oone None KKNO3
two Clone MgMgCl2
one Clone NaNaCl
ContainsFormula
• How many of each type of atom does the formula of the salt represent?
Name of Salt Formula Contains
calcium chloride CaCl2 Ca Cl
sodium sulphate Na2SO4 Na S O
magnesium sulphate MgSO4 Mg S O
magnesium nitrate Mg(NO3)2 Mg N O
calcium sulphate CaSO4 Ca S O
one
two
one
one
one
two
one
one
two
one
four
four
six
four
Activity
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
Neither H nor Cl balance.Need 2 HClNeither H nor Cl balance.Need 2 HCl
magnesium + hydrochloric acid
magnesium chloride
+ hydrogen
Mg + HCl MgCl2 + H2
Mg + 22HCl MgCl2 + H2
• 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.
Already balances; No changeAlready balances; No change
magnesium + sulphuric acid
magnesium sulphate
+ hydrogen
Mg + H2SO4 MgSO4 + H2
Need 2 K on both sides Need 2 K on both sides
potassium + sulphuric acid
potassium sulphate
+ hydrogen
K + H2SO4 K2SO4 + H2
2K2K ++ HH22SOSO44 KK22SOSO44 ++ HH22
Activity
Metals with Hydrochloric Acid
2
hydrogen+magnesium chloride
hydrochloric acid
+magnesium
Mg + HCl MgCl2 + H2
No reactionhydrochloric acid
+copper
Cu + HCl - -
hydrogen+aluminium chloride
hydrochloric acid
+aluminium
Al + HCl AlCl3 + H2
hydrogen+calcium chloride
hydrochloric acid
+calcium
362 2
Ca + HCl CaCl2 + H22
2
Metals with sulphuric and nitric Acid
hydrogen+zinc sulphatesulphuric acid+zinc
Zn + H2SO4 ZnSO4 + H2
hydrogen+magnesium nitrate
nitric acid+magnesium
Mg + HNO3 Mg(NO3)2 + H2
hydrogen+iron nitratenitric acid+iron
Fe + HNO3 Fe(NO3)3 + H2
hydrogen+calcium sulphate
sulphuric acid
+calcium
362 2
Ca + H2SO4 CaSO4 + H2
2
Metal oxides and acids
Metal oxide + acid a salt + water
• 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
Acid
Oxide
water+copper sulphate
sulphuric acid
+Copper oxide
Metal oxides and acids
Metal oxide + acid a salt + water
water+zinc sulphate
sulphuric acid+zinc oxide
water+sodium chloride
hydrochloric acid
+sodium oxide
water+iron nitratenitric acid+iron oxide
ZnO + H2SO4 ZnSO4 + H2O
Na2O + 2HCl 2NaCl + H2O
Fe2O3 + 3HNO3 Fe(NO3)3 + 3H2O
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.
water+calcium chloride
hydrochloric acid
+calcium carbonate
carbon dioxide
+
Metal carbonates and acids
Metal carbonate + acid a salt + water + carbon dioxide
water+zinc sulphate
sulphuric acid
+zinc carbonate
ZnCO3 + H2SO4 ZnSO4 + H2O + CO2
+ carbon dioxide
water+sodium chloride
hydrochloric acid
+sodium carbonate
+ carbon dioxide
water+nickel nitrate
nitric acid+nickel carbonate
Na2CO3 + 2HCl 2NaCl + H2O + CO2
+ carbon dioxide
NiCO3 + 2HNO3 Ni(NO3)2 + H2O + CO2
2. Which of these is NOTNOT a typical property of metals?
A. conduct
B. strong
C. dense
D. brittle
3. What is the symbol for Gold?
A. Go
B. Au
C. Ag
D. au
4. Which of the following elements is not a metal?
A. copper
B. lead
C. lithium
D. 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) Potassium chloride
B) Sodium nitride
C) Aluminium sulphate
D) Calcium nitrate
Which of these metals might not react with hot dilute acid?
A) Sodium
B) Calcium
C) Silver
D) Iron
Which of these substances would not neutralise an acid?
A) Silver nitrate
B) Sodium carbonate
C) Calcium oxide
D) Magnesium hydroxide
What number must replace X to balance the equation?
Fe(OH)3 + X HCl 3H2O + FeCl3
A)1B)2C)3D)4
What number must replace X to balance the equation?
CaCO3 + X H2SO4 H2O + CaSO4 + CO2
A) 1B) 2C) 3D) 4