Answer:
I am not sure of the answer but it is between A and C but my final answer is gonna be C.
Answer:
positive 3/2
Step-by-step explanation:
In the balanced reaction
2 Fe + O₂ → 2 FeO
2 moles of iron (Fe) react with 1 mole of molecular oxygen (O₂) to produce 2 moles of iron oxide (FeO). The ratio of Fe to FeO is 1-to-1, so if one starts with 42.4 mol of Fe, one will end up with the same amount of FeO, 42.4 mol.
Look up the molar mass of Fe and O:
• Fe = 55.845 g/mol
• O = 15.999 g/mol
Then the molar mass of FeO is approximately 71.835 g/mol, and so the mass of 42.4 mol of FeO is
(42.4 mol) × (71.835 g/mol) ≈ 3050 g
Fraction of girls = 1 - 3/7 = 4/7
4/7 is equivalent to 72 girls
1/7 .. .. ............. 72 / 4 = 18
Total number of children = 7/7 = 18*7 = 126 Answer