In the following problem we observed only two pairs of equivalent proton i.e.hc and hd ,then how can be five signals in a molecule?

For Hc & Hd we will get 2 signal. But Ha , Hb ,He there will be signal for this as well

so here total 5 signals observed

got it??

check it

here check the POS. all the proton along POS gives different signals while mirror image up side protons and down side protons gives same signals