iMac single ram stick capacity

Maybe one of you will know this. I just bought what I thought was a 32gb ram upgrade for my mid 2010 iMac. 4 sticks of 8gb. I installed them and turned the machine on and then checked to verify it was actually 32gb. It said that two of my ram slots had 24gb in them and 2 slots had 8gb sticks in which would total 64gb. Is this a problem? Does a single ram stick have that kind of capacity? My computer only can use 32gb and it seems to work but something about this seems dicey to me. I would appreciate any clarification on this. Thanks!!