A student tested a 0.1 M aqueous solution and made the
following observations conducts electricity, turns blue litmus to red and reacts
with Zn(s) to produce gas bubbles. The compound that could be the solute in
this solution is HBr. The answer is number 3.
The empirical formula is obtained by calculating the mole ratios of the atoms in the elements.
The number of moles =mass/ R.A.M
For hydrogen, no. of moles=8/1=8
For oxygen, no. Of moles=64/16=4
The tabular solution is attached.
Answer: a
Explanation:
Set up a ratio and solve.
7.9 • 120 / 160 = 5.925
Balanced equation:
2 Fe₂O₃ + 3 C → 4 Fe + 3 CO₂
number of moles of Fe₂O₃ = weight (g) / molar mass = (2.86 x 10⁴ g) / 159.69 g/mol = 179 moles
number of moles of C = (9.05 x 10³) / 12 = 754.16 moles
2 moles of Fe₂O₃ reacts with 3 moles of C
so 179 moles of Fe₂O₃ need 268.5 moles of C only
so carbon present in excess (754.16) and Fe₂O₃ is the limiting reactant so the number of moles used from Fe₂O₃ will be all the 179 moles
1
the lower the number the higher the ph and the more acidic it is
