Why be interested in cobalt chloride anyway? It is an unusual material in the way it changes colour, particularly in the presence of water. Anhydrous cobalt chloride, CoCl2, is blue in colour. As it absorbs water, it turns pink.
Why is cobalt chloride blue?
Cobalt (III) chloride (CoCl3) is an inorganic compound of cobalt and chlorine. It is a sky blue colour compound. Cobalt chloride changes the colour in response to the humidity. As the humidity increases the cobalt chloride changes the colour from sky blue to the purple and then to the pink.
Why does cobalt chloride turn blue when HCL is added?
Initially, the beaker contains a red-pink solution of cobalt (II) chloride, present as [Co (H2O)6] 2+ions and chloride ions. When hydrochloric acid is added, the added chloride ions shift the equilibrium position in favour of blue [CoCl4]2- ions and water.
How does the color of anhydrous cobalt II chloride change when water is added?
Anhydrous cobalt(II) chloride is blue in blue in colour but on dissolving in water it changes to pink in colour because. It changes to pink in colour with the change in coordination number to six.
What happens when you add HCl to cobalt chloride?
If you add concentrated hydrochloric acid to a solution containing hexaaquacobalt(II) ions (for example, cobalt(II) chloride solution), the solution turns from its original pink colour to a dark rich blue. The six water molecules are replaced by four chloride ions. The reaction taking place is reversible.
What does cobalt chloride indicate?
: a chloride of cobalt especially : the dichloride CoCl2 that is blue when dehydrated, turns red in the presence of moisture, and is used to indicate humidity.
Does cobalt dissolve in HCL?
All cobalt oxides dissolve in hydrochloric acid .
What happens when you add silver nitrate to the blue cobalt chloride solution?
Addition of AgNO3 to the blue solution of CoCl4 2– results in the formation of a white precipitate of AgCl, via the reaction Ag+(aq) + Cl–(aq) → AgCl(s), and a pink solution of Co(H2O)6 2+.
What is the effect of water on blue cobalt II chloride?
It is an unusual material in the way it changes colour, particularly in the presence of water. Anhydrous cobalt chloride, CoCl2, is blue in colour. As it absorbs water, it turns pink.
What can dissolve cobalt?
It is readily soluble in warm dilute mineral acids forming cobaltous salts. Cobaltous hydroxide, Co(OH) 21 is formed when a cobaltous salt is precipitated by caustic potash in the absence of air.
What is the symbol of cobalt?