A few different sources indicate that Hershey's cocoa powder has between 8 and 9 mg of caffeine per tablespoon. That may vary a little from brand to brand, but not enough to matter much.
Not much at all. An entire chocolate bar has about as much caffeine as a decaf cup of coffee. There's no added caffeine in hot cocoa mixes (at least for common varieties) and much less chocolate than a bar. It's probably extremely low.
One tablespoon maximum
1tbsp of cocoa powder = 6g I say it's 5.2 grams, according to wolframalfa computational search engine.
3 level tablespoons of cocoa powder plus 1 tablespoon of butter or shortening equals 1 square cube of unsweetened baking chocolate.
20 mg / oz - http://coffeetea.about.com/library/blcaffeine.htm While the above referenced content of caffeine may be common in commercially processed chocolate, it is not always so. The caffeine content of chocolate has been the subject of much debate -- and conflicting research from the scientific community. Some data sugests that there is caffeine content in the cocoa bean, though the International Cocoa Organization states that the caffeine content is very low. Other data suggests that there is no caffeine in cocoa, and that any caffeine present has been added by manufacturers. It's also interesting to note that some data suggests that the caffeine only resides in the fiber and husk that surround the cocoa bean. In that case, if the beans are properly cleaned, there should be virtually NO caffeine in the resulting chocolate product. - http://www.thefivereasons.com/
12 oz of cocoa powder!
Substitution for 1 ounce (30 grams) unsweetened chocolate: 3 tablespoons (18 grams) unsweetened natural cocoa powder plus 1 tablespoon (17 grams) unsalted butter or shortening
100 grams of Cocoa powder is equivalent to 0.88 cups of cocoa powder, which is about 7/8 of a cup.
Presweetened cocoa powder is a commercial product, not something made in the home kitchen. It is cocoa powder that already is combined with sugar and other ingredients.
Usually yes. Some recipes specify "baking" cocoa powder just so that nobody gets confused and uses "drinking chocolate mix" instead (since this contains sugar and milk powder which would throw off the recipe).
If you're looking for good quality cocoa powder, then look no further than the Selfridges & Co website. They offer a 250g pack of Chococru Cocoa Powder for 14.99 GBP.
There are 0 calories in Baking Powder...;)