Answer:
1.86% NH₃
Explanation:
The reaction that takes place is:
- HCl(aq) + NH₃(aq) → NH₄Cl(aq)
We <u>calculate the moles of HCl that reacted</u>, using the volume used and the concentration:
- 32.27 mL ⇒ 32.27/1000 = 0.03227 L
- 0.1080 M * 0.03227 L = 3.4852x10⁻³ mol HCl
The moles of HCl are equal to the moles of NH₃, so now we <u>calculate the mass of NH₃ that was titrated</u>, using its molecular weight:
- 3.4852x10⁻³ mol NH₃ * 17 g/mol = 0.0592 g NH₃
The weight percent NH₃ in the aliquot (and thus in the diluted sample) is:
- 0.0592 / 12.949 * 100% = 0.4575%
Now we <u>calculate the total mass of NH₃ in the diluted sample</u>:
Diluted sample total mass = Aqueous waste Mass + Water mass = 23.495 + 72.311 = 95.806 g
- 0.4575% * 95.806 g = 0.4383 g NH₃
Finally we calculate the weight percent NH₃ in the original sample of aqueous waste:
- 0.4383 g NH₃ / 23.495 g * 100% = 1.86% NH₃
<span>A)How many moles of O2 are required for the complete combustion of 2.2 g of C3H8 to form CO2 and H2O?
C3H8 + 5O2 = 3CO2 + 4H2O
2.2 g C3H8 ( 1 mol / 44.11 mol ) ( 5 mol O2 / 1 mol C3H8) = 0.25 mol O2
b)A 65.25 g sample of CuSO4•5H2O (M = 249.7) is dissolved in enough water to make 0.800 L of solution. What volume of this solution must be diluted with water to make 1.00 L of 0.100 M CuSO4?
M1V1 = M2V2
[65.25 ( 1 / 249.7 )/ 0.800 L] (V1)= 0.100 (1.00 L)
V1 = 0.31 L or 310 mL </span>
The correct answer is
<span>B. An attraction between the positive end of one molecule and the negative end of another.
Because the dipole is the molecule that has </span> the positive end and the negative end,
Brass is a homogeneous mixture.
In the liquid state, the copper and zinc formed a solution.
They did not separate from each other when the brass solidified.
Thus, brass is a solid solution.
