The universe contains only about one-tenth as many helium atoms as hydrogen atoms. But a hydrogen atom is only one-quarter the mass of a helium atom. So approximately what is the ratio of the universe's helium to hydrogen by mass

During chemistry class, carl performed several lab tests on two white solids. the results of three tests are seen in the data table. based on this data, carl has concluded that substance b must have bonds.

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.

When water dissolves sugar, which process is not involved? o dissociation o hydration o surface area of the solute increases sa