To draw a Lewis structure for a covalent compound, begin by

calculating A, the available

electrons, and N, the needed

electrons.

What is N for silicon

tetrachloride, SiCl4?

Enter

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.

Design techniques and materials that reduce the negative environmental impact of a structure are referred to as

The mass of a neutron is equal to the mass of a proton plus the mass of an electron. true or false false true