The answer is d: Combustion, because it is the so-called combustion of methan. (Check your lesson)
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>
Answer:
Cr3+ is green and V2+ is purple. Cr3+ and V2+ are both d3 so there can be a lot of movement between energy levels to produce colored light. Cd2+ and Hg2+ are both d10 (full d orbital, much less electron movement).
Explanation:
The more finely divided the solid is, the faster the reaction happens. A powdered solid increases the rate of the reaction than the same mass present as a single lump. The powdered solid has greater surface are than the single lump.
Catalytic Converter is the correct answer. Toxic gases are produced in the combustion reaction of an engine, and when this gas adheres to the converter, it’s chemically transmuted into something that’s harmless.