Which is more stable ccl3- or cf3-
Since FLOURINE is more electronagative than CHLORINE , there is more inductive effect on carbon of CCl3(-) than in CF3(-) which stablises its negative charge. The negative charge on the carbon in CCl3(-) is further stablised in the vacant d-orbital of Chlorine which is not possible in case of CF3(-)
CCl3- will be more stable.
However, flourine is more electronegative than chlorine but it lacks d-orbital which is present in Chlorine. Due to lack of d-orbital in flourine and its presence in chlorine , even chlorine being less electronegative ,DUE TO BACK BONDING, stabilses the negative charge and hence the whole ion.