posted by Anonymous .
a mixture of NaCl and NaBr has a mass of 2.06 g and is found to contain 0.75 g of na
what is the mass of NaBr in the mixture ?
Best Answer - Chosen by Voters
Let UNITs guide you; always USE THEM in your calculation to prevent errors
moles of Na in samp = 0.78 g/ atwt Na = ??
x moles NaBr * MW NaBr + (moles Na - x moles NaBr) * MW NaCl = 2.01 g
x moles NaBr = [2.01 g - moles Na * MW NaCl] / [MW NaBr - MW NaCl] = ??
g NaBr = x moles NaBr * MW NaBr
wt fraction = g NaBr/2.01g = ?? (0.049 wt fraction of NaBr)
Plug and SOLVE
Or do you need more than this?