For names of market products, you can verify what you have by searching some online retailers. (Is it OK to give names?) You can even search in English in some. You'll have better luck at online open market platforms where multiple retailers can post their products. This is possible because retailers who sell imported goods sometimes use both the original (mostly English) name and Korean for their item titles. You may find it difficult to find consensus for some items like epsom salt, but that's just because, well, there is no widely accepted translation word for them.
For baking soda as food ingredients or household goods, you say 베이킹소다. 중조 is more like an archaic/academic term, far from daily usage.
Citric acid is mostly known as 구연산, but 시트르산 is also used.
Cornstarch is 옥수수 전분.
Epsom salt isn't widely used in Korea so there seems to be no fixed word, but market retailers seem to use either 엡솜(엡섬)염, 엡솜(엡섬) 솔트, and more rarely, also 엡솜(엡섬) 소금.
Oil in general is 기름, but the suffix -유(油) can be attached to some (but not all) ingredient names. 올리브유 (olive oil) is one of them. 콩기름 (soybean oil) is also known as 대두유(大豆油). Almond oil is mostly known just as 아몬드오일.
Essential oil by itself is most commonly known as 에센셜 오일, but when you attach it to an ingredient, 정유 is also used. (eg 편백 정유)
I never heard of mica powder ever, but it seems they sell it by the name 마이카.
And water is surely 물. In compound words it can be -수(水) or 워터(from water),
(Disclaimer: this answer is 100% based in South Korean experience. I don't have any idea at all how they call these things on the other side of the DMZ.)
: The choice between -유 and 기름 attached to ingredient names seems to be quite arbitrary, and you hardly can mix them up. (I would say 올리브 기름 and 콩유 are not valid words.)