Melvin is exploring the different kinds of changes that can happen to substances. After reading about the kinds of changes that occur, he saw some rust on a pipe that was going into his house. What kind of change is the formation of rust? A. reactant
B. physical
C. chemical

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.

How many moles of gas are present if p=11 atm, v=12l, t=185k?

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure