Grant found the mass of an empty crucible and lid to be 62.549 g. After he added an unknown, the mass was 63.089 g. The crucible and lid and unknown were
heated strongly for 10 minutes. After cooling, the mass of the crucible and lid and sample
were found to be 62.928 g. Grant also performed a flame test on a sample of his unknown,
and found it produced a violet flame. Is the unknown NaHCO3, Na2CO3, KHCO3, or K2CO3?
Explain the reasoning used to arrive at your answer.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

answerapplication program;