How many of the following metal chlorides impart characteristic colour to the oxidising flame?
LiCl, NaCl, KCl, RbCl, BeCl₂ , CaCl₂ , SrCl₂ , BaCl₂ , MgCl₂

Question

How many of the following metal chlorides impart characteristic colour to the oxidising flame? LiCl, NaCl, KCl, RbCl, BeCl 2 , CaCl 2 , SrCl 2 , BaCl 2 , MgCl 2

TestHub · Accepted Answer

Alkali metals (Li, Na, K, Rb) and heavier alkaline earth metals (Ca, Sr, Ba) easily excite their valence electrons in a flame, imparting characteristic colors.

BeCl₂ and MgCl₂ do not impart any color because beryllium and magnesium have very small atomic sizes and extremely high ionization energies. Their valence electrons are too tightly bound to be excited by a Bunsen flame.

The 7 chlorides that show color are LiCl (crimson), NaCl (yellow), KCl (lilac), RbCl (red-violet), CaCl₂ (brick red), SrCl₂ (crimson), and BaCl₂ (apple green).

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