How many grams of dry nh4cl need to be added to 2.00 l of a 0.600 m solution of ammonia, nh3, to prepare a buffer solution that has a ph of 8.74? kb for ammonia is 1.8×10−5?

In a heat engine of 1000 j of heat enters the system and the piston does 500 j of work what is the final internal energy of the system if the inital energy was 2000 j we have to do all of these down here 1)write the equation 2)list out your know variables 3)plug the numbers into the equations 4)solve 5)write your solution statemtn that includes inital energuy and final energuy added

Consider the reaction: 2al(s) + fe2o3(s) → al2o3(s) + 2fe(s) the δhf for fe2o3(s) = -824.3 kj/mole. the δhf for al2o3(s) = -1675.7 kj/mole. finish the equation. δhrxn = [(1)( kj/mole) + (2)( kj/mole)] - [(1)( kj/mole) + (2) ( kj/mole)]

Which statement best describes isomers? a. isomers are alcohols that have the same functional group. b. isomers have at least one carbon-carbon double bond. c. isomers have the same molecular formula but different structural properties.