We are doing an experiment where we have to find the percent of copper in a nickel (coin). We believe we already know how to separate the copper from the nickel (we did a similar experiment with brass). However, we were wondering how to dissolve the nickel so the copper can be extracted out. Also, would the brass procedure be the same, because we think there might be things in nickel that are not in brass and we don't do not know it that would have effect it.