# How to calculate molar mass of (6)UO2+2D and (6)UO2OH+D

For a hydrogeochemistry project, I want to calculate the molar masses of some compounds. I came across a problem when encountering species like (6)UO2+2D (aq) and (6)UO2OH+D(aq). I don't know what the (6) and the +2D mean.

I started off with IPC-MS results for several trace elements and fed them to VMinteq for the speciation modelling. I tried to google the species, but that query produced no useful results. I am no chemist and I don't know "how" or "where" to search efficiently for an answer.

EDIT: another (6) appeared in FA1-UO2(6)(aq)

• Welcome to the Chemistry SE! You should take the tour and, if you have any further questions about the site, visit the help center. I'm unfamiliar with the topic, are you saying you got these species from the modeling program or you saw them in a paper? Best of luck in getting an answer! – Tyberius Mar 28 '17 at 16:44
• I'm completely unfamiliar with both those (6) and +D notations. Must be field-specific. – hBy2Py Mar 28 '17 at 16:47
• Those species were produced by vMinteq, the modeling program. Thanks for the links, I'll make sure to study the help sites to cozy into the mores and fashion of chemSE. – thymaro Mar 28 '17 at 16:48
• $m/z$ is the ratio between the mass and the charge of a particle hitting the MS detector. That would allow to guess whether the (6) means "six of these fragments", or "a fragment that has six of these things in it" – hBy2Py Mar 28 '17 at 16:53
• The (6) for uranium in this Minteq output refers to the valence number for uranium here (+6), which means that $\ce{UO2}$ is really $\ce{UO2^{2+}}$. The D is very likely deuterium, but I cannot confirm that from the user's manual. – Todd Minehardt Mar 28 '17 at 17:28