16
Calcium and strontium
Calcium
Highly flammable
Ca
R15: Contact with water liberates highly flammable gases.
Dangerous with: WATER, ACIDS. Hydrogen is formed which may ignite from the
heat of reaction under certain circumstances.
SULFUR. An explosive reaction occurs.
HYDROXIDES and CARBONATES of SODIUM, POTASSIUM and other ALKALI
METALS. Reactions may be explosive.
The metal is difficult to ignite but burns vigorously when lit and is difficult to
extinguish. Small fires are best extinguished by smothering with dry sand.
Store: FW
Disposal: W1, W5
A white oxide layer may form on the turnings.
W5:
Use a fume cupboard with no sources of
ignition present.
Strontium
Highly flammable
Irritant
F
Sr
F
I
R11: Highly flammable. R14: Reacts violently with water. R38: Irritating to skin.
Store: FW
It is sometimes supplied under argon. Once opened, it can
be stored dry in an air-tight container or stored under liquid
paraffin as with barium.
Disposal: W1, W5
W5:
Use a fume cupboard with no sources of
ignition present.
Emergencies: see standard procedures on Hazcard E, BUT ALSO:
If particles
Flood the eye with gently-running tap water until a first aider arrives. Send the casualty to hospital and
enter the eyes: ensure that irrigation is continued during the journey.
For emergencies, see Hazcard E as well as more detailed information which may be on this Hazcard.
© CLEAPSS 2007
16
Calcium and strontium
Activity
Reaction of
calcium with
water
User
Y7
Control measures
Wear eye protection.
Reaction of
calcium with
dilute acids
Y7
Wear eye protection.
Reaction of
strontium with
water and
dilute acids
Burning
calcium
TT
Wear eye protection.
TT
Wear eye protection.
Must be carried out behind
safety screens because there
is much sputtering of whitehot particles.
Action of
chlorine on
calcium
TT
Wear eye protection.
Use a fume cupboard.
Not to be done in a gas jar.
Model risk assessments
Experimental points
Hydrogen is evolved. The resulting solution will be alkaline and
irritating to the skin. If a test tube is a quarter-filled with water,
the amount of calcium added must be limited because frothing
can occur. Alternatively, use a tall-form beaker, at least halffilled with water, and collect hydrogen for identification in test
tubes, via a small inverted funnel. This reaction is not suitable
for the preparation of hydrogen.
-3
If a test tube is a quarter-filled with 0.4 mol dm hydrochloric
acid, the amount of calcium added must be limited to 1 to 3
granules or a turning at a time. There is very little reaction with
dilute sulfuric(VI) acid because the calcium is coated with
calcium sulfate(VI) which is only slightly soluble in water.
Hydrogen is evolved.
The metal is very difficult to ignite. Use fresh turnings which are
easier to ignite than granules. It is usually necessary to wrap the
sample partially in ceramic paper in order to ignite the calcium
easily and this makes sputtering more likely. Apply heat directly
from a supported Bunsen burner or, better still, a portable flame
torch suitable for kitchen use. See L195, Safer Chemicals, Safer
Reactions.
Chlorine should be passed over calcium in a combustion tube
which is gradually heated to a high temperature.
For emergencies, see Hazcard E as well as more detailed information which may be on this Hazcard.
© CLEAPSS 2007