The diffusivity of chloroform in air was measure using an arnold cell at 298 k and 1 atm. the liquid density of chloroform at 298b k is 1.48 g/cm3 and its vapor pressure at 298 k is 2.67 x104 pa. initially, the liquid chloroform surface was 7.4 cm from the top of the tube, and after 10 hours the liquid surface dropped to 6.96 cm. if the concentration of chloroform is zero at the top of the tube, what would the gas diffusion coefficient of chloroform in air?

Nickel crystallizes in the face-centered cubic (fcc) lattice. the density of the metal is 8902 kg/m3. calculate the radius of a nickel atom.

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

Electromagnets coils of wire paper clips picked up 10 3 15 6 20 9 25 12 ms. owens' class was studying magnets. ms. owens showed her students how to make an electromagnet using a nail, a d-cell battery, and plastic coated wire. the students wrapped the wire around the nail and then attached the ends to the battery. when they were finished, they tested their magnets by investigating how many paperclips their magnets could pick up. they also tested whether they could increase the strength of their electromagnets by using more coils of wire. they recorded the class average of their results in the data table seen here. ms. owens asked her students to graph their data in a line graph. how should the students label the x-axis on their line graph? a) size of battery b) number of paper clips c) number of coils of wire d) strength of electromagnet