Answer:
17.3 g Cr
Explanation:
To find the mass of chromium, you need to (1) convert moles Si to moles Cr (using the mole-to-mole ratio from equation coefficients) and then (2) convert moles Cr to grams Cr (using the atomic mass). It is important to arrange the conversions in a way that allows for the cancellation of units. The final answer should have 3 sig figs to match the sig figs of the given value (0.250).
3 Si + 2 Cr₂O₃ ---> 4 Cr + 3 SiO₂
^ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ^
Atomic Mass (Cr): 51.996 g/mol
0.250 moles Si      4 moles Cr       51.996 g
-------------------------  x  --------------------  x  -------------------  =  17.3 g Cr
                   3 moles Si        1 mole
