The grade scales in my classes are always absolute, not curved. To find out of you have correctly answered a question from a previous exam, you need to show your work to your T.A. or to me for verification. Obviously, this can not be done at the last minute. On the chiral or achiral molecule, when we reflect the image and try to figure out if it is superimposible or not, can we rotate anyways, such as verticaly.
Enantiomers are non-superimposable mirror image structures.
Chelates may bridge two metal atoms, but that is beyond thescope of our present discussion. One may need to do several manipulations to determine whether mirror-image structures are chiral or not. All the material in Ch. 3, Ch. If this doesn't answer you question, see me in class. Like problem number 41,c and d have the ligands, en and edta.