Explaining some of the reactions between metals/water and metals/acid (high school science)

1. Jacques Zeefenbergen © 2012

2. Some metals react very quickly and
easy with acids. Normally, “light”
metals react vigorously with acids.
However, some metals react slower
with acids. The heavier a metal gets,
the slower and more difficult the
reaction
eg. Light metals Na, K, Ca
eg. Heavier metals Mg, Al, Zn, Pb2012
Jacques Zeefenbergen ©

3. Diluted acid is acid mixed with a bit of
water (to make the solution weaker).
The acid will be in the aqueous state.
eg. HCl(aq)
Concentrated acid is strong and
pure. It is NOT mixed with water
eg. HCl(l)
Jacques Zeefenbergen © 2012

4. Most reactions between metals and
diluted acids are SINGLE
REPLACEMENT reactions (a metal will
replace the hydrogen of the acid).
During the reaction, hydrogen gas is
released as a product.
H2 (g)
Jacques Zeefenbergen © 2012

5. Examples of reaction between metals
and acids:
Ca(s) + 2 HCl (aq)  CaCl2 (aq) + H2 (g)
2 Al + 6 HNO3 (aq) 
2 Al(NO3)3 (aq) + 3 H2 (g)
Jacques Zeefenbergen © 2012

6. Most reactions between metals and
concentrated acids are a combination
of SINGLE REPLACEMENT and
DECOMPOSITION reactions
(a metal will replace the hydrogen of
the acid AND some nitrate will
decompose)
Jacques Zeefenbergen © 2012

7. Reaction between metals and
concentrated acids acids:
Cu(s) + 4 HNO3 (l) 
Cu(NO3)2 (aq) + 2 NO2 (g) + 2H2O (l)
Jacques Zeefenbergen © 2012

8. Jacques Zeefenbergen © 2012

9. Some metals react very quickly and
easy with water. Normally, “light”
metals react vigorously with water.
However, some metals react slower
with water. The heavier a metal gets,
the slower and more difficult the
reaction. Water can have more energy
if it heats up. The more energy water
has, the better the reaction © 2012
Jacques Zeefenbergen

10. Examples of reaction between metals
and cold water:
2Na (s) + 2H2O (l) 
2 NaOH (aq) + H2 (g)
So, metals + cold water (H2O (l)) give
hydroxide and hydrogen gas (H2 (g))
Jacques Zeefenbergen © 2012

11. Examples of reaction between metals
and steam:
Mg (s) + H2O (g) 
MgO (s) + H2 (g)
So, metals + steam(H2O (g)) give a
metal oxide and hydrogen gas (H2 (g))
Jacques Zeefenbergen © 2012