BaSO₄ is relatively harmless, but BaS is highly toxic.
BaSO₄ is quite insoluble (240 µg/100 mL). It is a <em>mild irritant</em> in cases of skin contact and inhalation. However, it is <em>safe enough</em> that health professionals ask patients to drink a suspension of BaSO₄. The Ba is opaque to X-rays, so it makes the stomach and intestines more visible to radiographers.
BaS is soluble (7.7 g/100 mL). It reacts slowly with water and more rapidly in the acid conditions of the stomach to <em>release H₂S</em>.
BaS + 2HCl ⟶ BaCl₂ + H₂S
An H₂S concentration of 60 mg/100 mL can be <em>fatal within 30 min</em>.
<em>Don’t eat barium sulfide!</em>
Sorry if I'm wrong but I think that it is B.
Answer:
For the first question, to determine the total number of molecules of nitrogen dioxide, first make use of the molar mass of the nonpolar compound and then use that to find the total number of moles and then subsequently after make use of the ratio for the Avogadro's number to determine the total number of molecules of this compound.
For the final question, do the inverse, where we make use of the molecules of the compound and then use Avogadro's number to determine the moles of the compound and then use the same molar mass of the compound to determine the grams of the Nitrogen Dioxide.
