When a solution of ammonium chloride, nh4cl, is added to a solution of lead (ii) nitrate , pb(no3)2, a white precipitate, pbcl2, forms. which of the following is the total ionic equation for this reaction?

a) 2 nh4cl(aq)+pb(no3)2(> pbcl2(s)+2 nh4no3 (aq)
b) 2 nh4+(aq)+2cl-(aq)+pb2+(aq)+2no3-(&g t; pbcl2(s)+2nh4+(aq)+2no3-(aq)
c) pb2+(aq)+2cl-(> pbcl2(s)
d) pb2+(aq)+cl2-(> pbcl2(s)

How does the principle of electromagnetism explain the interaction between earth’s magnetic field and the solar wind?

Tooth enamel consists mainly of the mineral calcium hydroxyapatite, ca_10(po_4)_6(oh)_2. trace elements in teeth of archaeological specimens provide anthropologist with clues about diet and diseases of ancient people. students at hamline university measured strontium in enamel from extracted wisdom teeth by atomic absorption spectroscopy. solutions with a constant total volume of 10.0 ml contained 0.726 mg of dissolved tooth enamel plus variable concentrations of added sr. added sr find the concentration of sr in the 10 ml sample solution in parts per billion = ng/ml. find the concentration of sr in tooth enamel in parts per million = mu g/g.

You just calculated that the heat of fusion for chloromethane is 6400 j/mol. the heat of fusion for hydrogen is 120 j/mol.? which of the following account for this difference? more than one correcta. chloromethane can absorb more energy at the same temperature. b. hydrogen has stronger intermolecular forces than chloromethane. c. hydrogen molecules can pack more closely than chloromethane molecules. d. chloromethane experiences dipole-dipole interactions. e. chloromethane has a higher molar mass than hydrogen.