How many grams of testosterone, c19h28o2 (288.4 g/mol), must be dissolved in 299.0 grams of benzene to reduce the freezing point by 0.500°c ? refer to the table for the necessary boiling or freezing point constant.

solvent

formula

kb (°c/m)

kf (°c/m)

water

h2o

0.512

1.86

ethanol

ch3ch2oh

1.22

1.99

chloroform

chcl3

3.67

benzene

c6h6

2.53

5.12

diethyl ether

ch3ch2och2ch3

2.02

? g testosterone.

Which statement correctly describes metallic bonds? a. they form when certain atoms lose electrons and other atoms gain electrons. b. they involve an attraction between anions and cations. they always involvpoth a metal and a nonmetal. d. they can only form between atoms of the same element. e. they form because electrons can move freely between atoms.

Since the gas in your graduated cylinder is a mixture of butane and water vapor, you must determine the partial pressure of the butane, pbutane, alone. to do this, consult a reference and record the partial pressure of the water vapor, pwater, at the temperature you recorded. use the following formula to compute the partial pressure of the butane. pbutane = atmosphere - pwater use the following combined gas law formula and compute the volume that the butane sample will occupy at stp. (hint: convert both temperatures to kelvin.) pbutane x voriginal = pstandard x vfinal troom tstandard use the following ratio and proportion formula to determine the mass of butane needed to occupy a volume of 22.4 l at stp. grams of butane you used “x” grams of butane ml of butane corrected to stp = 22,400 ml compute the theoretical molar mass of butane based on its formula and the atomic masses on the periodic table. compare your experimental results from #3 to the theoretical value of #4, computing a percent error of your findings using this formula: % error = measured value - accepted value x 100 accepted value use the following ratio and proportion formula to determine the mass of butane needed to occupy a volume of 22.4 l at stp. need asap

Nonpoint source pollution is difficult to control because it