Answer:
34,6g of (NH₄)₂SO₄
Explanation:
The boiling-point elevation describes the phenomenon in which the boiling point of a liquid increases with the addition of a compound. The formula is:
ΔT = kb×m
Where ΔT is Tsolution - T solvent; kb is ebullioscopic constant and m is molality of ions in solution.
For the problem:
ΔT = 109,7°C-108,3°C = 1,4°C
kb = 1.07 °C kg/mol
Solving:
m = 1,31 mol/kg
As mass of X = 600g = 0,600kg:
1,31mol/kg×0,600kg = 0,785 moles of ions. As (NH₄)₂SO₄ has three ions:
0,785 moles of ions× = 0,262 moles of (NH₄)₂SO₄
As molar mass of (NH₄)₂SO₄ is 132,14g/mol:
0,262 moles of (NH₄)₂SO₄× = <em>34,6g of (NH₄)₂SO₄</em>
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I hope it helps!
Answer:
The answer is acceleration.
Explanation:
Acceleration- When it comes to science, Force is defined as a "push or pull" of an object with mass that causes it to change velocity.
Balanced Force- This occurs when two forces of the same mass or size are acting on a particular object in opposite direction. The object being acted upon could <em>either stay in its place or move in a uniform speed and direction.</em>
Unbalanced Force- This occurs when the forces applied are not equal and are of different direction. For example, a 55-kg person pulling a 30-kg cart. The cart will move to the direction of the pull.
Thus, when forces acting on an object are unbalanced, it causes the object to accelerate. This acceleration is directly proportional to the "net force", but is inversely proportional to the mass or size.
<u>A net force</u> is the total amount of force that is acting on the object.
Answer:
Option B.
Explanation:
- 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂
First we <u>convert 9.90 g of Pb(NO₃)₂ into moles</u>, using its molar mass:
- 9.90 g ÷ 331.2 g/mol = 0.0299 mol Pb(NO₃)₂
Then we<u> convert moles of Pb(NO₃)₂ into moles of PbO</u>, using the stoichiometric coefficients:
- 0.0299 mol Pb(NO₃)₂ * = 0.0299 mol PbO
Now we<u> convert 0.0299 mol PbO into grams</u>, using its molar mass:
- 0.0299 mol PbO * 223.2 g/mol = 6.67 g PbO
So <em>6.67 g is the theoretical yield</em>. With that in mind <u>we calculate the percent yield</u>:
- % yield = 5.51 / 6.67 * 100 % = 82.6%
So the correct answer is option B.