L Pretest: Unit 4 Question 4 of 22
The hydrogen emission spectrum is shown below. What is the energy of the
410 nm emission line? (The speed of light in a vacuum is 3.00 x 10 m/s, and
Planck's constant is 6.626 x 10-34 J·s.)
-00
760 m
H
410 434
480
06
A. 4.85 10-19

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.

What is the correct term for living the most sustainable life you can within your current circumstances?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.