Given the following heats of combustion: c2h2(g) = -1300 kj/mole, h2(g) = -286 kj/mole, c2h6(g) = -1560 kj/mole, calculate the enthalpy change for the following reaction
c2h2(g) + 2h2(g) → c2h6(g)
a. -312 kj
b. -26 kj
c. +312 kj
d. -26 kj

What semimetal can form four single covalent bonds.

Fugu, also known as puffer fish, is a sushi delicacy that can also be lethal. puffer fish contain a powerful toxin that can kill an adult a few hours after ingestion. sushi chefs who prepare fugu must be specially trained because any contamination of the toxin-free areas of the fish can be deadly. recently this toxin has been put to good use, as scientists have discovered that a purified form of it can treat severe pain in cancer patients. this recent scientific discovery would fall under which area of chemistry? applied biochemistry pure organic chemistry pure physical chemistry applied inorganic chemistry

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.