Question

what is the reddish-brown solid that forms on the metal strip

Answer 1

Answer:

reddish brown solid that form on the metal strips is rust the formula of Rust is have e2o 3.62 o

Answer 2

It is rust or Fe2O3.

Edit: Oh, you meant when iron is immersed into cupric sulphate solution, then the reddish brown deposit is copper metal.