Which represents a double replacement reaction and would occur?
a) nh4no3(aq) + agcio3(aq) mc011-1.jpg agno3(aq) + nh4cio3(aq)
b) na2co3(aq) + cacl2(aq) mc011-2.jpg 2nacl(aq) + caco3(s)
c) naf(aq) + kcl(aq) mc011-3.jpg nacl(aq) + kcl(aq)
d) nacl(aq) mc011-4.jpg na+(aq) + cl-(aq)

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?

The two naturally occurring isotopes of chlorine are 35cl (34.969 amu, 75.77%) and 37cl (36.966 amu, 24.23%). the two naturally occurring isotopes of bromine are 79br (78.918 rm amu, 50.69%) and 81br (80.916 amu, 49.31%). chlorine and bromine combine to form bromine monochloride, brcl. 1. how many peaks will be present in a mass spectrum for brcl? the four combinations of molecule possible given these four isotopes are: 81br37cl, 81br35cl, 79br37cl, and 79br35cl. 2. what are the masses of the four different brcl molecules? express the masses using six significant figures, in decreasing numeric order (highest to lowest), separated by commas.

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.