Answer:
D im pretty sure cuz i prob had this test already
Explanation:
Okay so your answer for n is
Answer:
28.9 g
Explanation:
We know that we will need a balanced equation with masses, moles, and molar masses of the compounds involved.
<em>Gather all the information in one place</em> with molar masses above the formulas and masses below them.
: 159.69 28.01
Fe₂O₃ + 3CO ⟶ 2Fe + 3CO₂
Mass/g: 55.0
1. Use the molar mass of Fe₂O₃ to calculate the moles of Fe₂O₃.
2. Use the molar ratio of CO:Fe₂O₃ to calculate the moles of CO.
3.Use the molar mass of CO to calculate the mass of CO.
Answer:
Br
|
Br-P-Br
|
Br
Explanation:
To calculate the valance electrons, look at the periodic table to find the valance electrons for each atom and add them together. P is in column 5A, so it has 5, Br is in column 7A, so it has 7 (multiply by 4 since there are 4 Br atoms to give 28) and there is a 1- charge, so add one more electron. 5+28+1=34, so there are 34 electrons to place. P would be the central atom, so place it in the middle. Place each Br around the P (as shown above) with a a single line connecting it. Each line represents 2 electrons, so 8 total have been place, leaving 26 remaining. Place 6 electrons around each Br (2 on each of the unbonded sides), which leaves 2 electrons remaining. The remaining pair of unbound electrons will be attached to the P between any two Br atoms. Phosphorus doesn't have to follow the octet rule, so it actually ends up with 10 valance electrons.
Answer:
Boiling point of the solution is 100.78°C
Explanation:
This is about colligative properties.
First of all, we need to calculate molality from the freezing point depression.
ΔT = Kf . m . i
As the solute is nonelectrolyte, i = 1
0°C - (-2.79°C) = 1.86 °C/m . m . 1
2.79°C / 1.86 m/°C = 1.5 m
Now, we go to the boiling point elevation
ΔT = Kb . m . i
Final T° - 100°C = 0.52 °C/m . 1.5m . 1
Final T° = 0.52 °C/m . 1.5m . 1 + 100°C → 100.78°C
