CALCIUM - Ca

Properties of Calcium:

Alkaline earth metal, silver-white, ductile, fairly hard. In humid air is covered with a film of oxide-hydroxide. Colors the flame of gas burner to brown-red. Reactive, reacts with oxygen, nitrogen, hydrogen, halogens and other non-metals by heating. A strong reducing agent, reacts with water, dilute acids, ammonia.


Molar mass g/mol 40.078
Density g/cm3 1.54
Melting point °C 842
Boiling point °C 1495

Methods for preparation of Calcium:

CaH2 = Ca + H2 (over 1000°C).

4CaO + 2Al = 3Ca + (CaAl2)O4 (1200°C).

3CaCl2 + 2Al = 3Ca + 2AlCl3 (600-700°C).

CaCl2(liquid) → Electrolysis → Ca(on cathode) + Cl2↑(on anode).


Сhemical reactions with metal Calcium:

Ca + 2H2O = Ca(OH)2↓ + H2↑ (normal temp.),

2Ca + H2O(vapor) = CaO+CaH2 (200-300°C).

Ca + 2HCl(diluted) = CaCl2 + H2↑.

4Ca + 10HNO3(diluted) = 4Ca(MO3)2 + N2O↑ + 5H2O.

4Ca + 10HNO3(highly diluted) = 4Ca(NO3)2 + NH4NO3 + 3H2O.

Ca + H2 = CaH2 (500-700°C).

2Ca + O2 = 2CaO (over 300°C, burning on air).

Ca + E2 = CaE2 (normal temp., E = F; 200-400°C, E = Cl, Br, I).

Ca + S = CaS (150°C).

3Ca + N2 = Ca3N2 (200-450°C, burning on air),

3Ca + 2P(red) = Ca3P2 (350–450°C).

Ca + 2C(graphite) = CaC2 (550°C).

Ca + 6NH3(gas) = [Ca(NH3)6](e−)2(yellow) [normal temp.],

6Ca + 2NH3(gas) = Ca3N2 + 3CaH2 (600-650°C).

Ca + 6NH3(liquid) = [Ca(NH3)6](blue) [-40°C, in the atm. of Ar],

Ca + 2NH3(liquid) = Ca(NH2)2↓ + H2↑ (catalyst Pt).


 

Did you know?

Hot peppers get their heat from a molecule called capsaicin. While the molecule acts as an irritant to mammals, including humans, birds lack the receptor responsible for the effect and are immune to the burning sensation from exposure.