a toxic herbicide, C12 H14 N2 ⋅ 2CH3 SO4, applied to food and flower crops and to highway borders as a defoliant and weed-killer.
Erm, that formula looks wrong to me. Paraquat (I am reliably informed by google) is a bipyridyl chloride, not a sulfate. That formula looks impossible, it looks like it's counting the methyl groups in the main structure and the adduct.
It should be C12 H14 N2 SO4 or in the notation you used C10 H8 N2 . 2(CH3) SO4 which is messy, it doesn't show if there's one sulfate or two.
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