# chemistry

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calculate the mass given element of each of the following compounds
a) brimine in 50.0 potassium bromide, KBr
b) Chromium in 1.00 kg sodium dichromate Na2Cr2O7

• chemistry -

Here is how to do (a). You can do (b) the same way.

The molar mass of KBr is 39.1 + 79.9 = 119.0. I just added the atomic masses of one K and one Br atom.
50.0 g is 50.0/119.0 = 0.420 moles.
The mass of bromine is the sample is 79.9 g/mole* 0.420 moles = 33.6 g

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