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mixas84
1 month ago
12

The mean free path of a helium atom in helium gas at standard temperature and pressure is 0.2 um.What is the radius of the heliu

m atom in nanometers?
Physics
1 answer:
Yuliya22 [3.3K]1 month ago
5 0

Answer: 0.10233nm

Explanation:

The mean free path of an atom can be calculated using the following equation:

\lambda=\frac{RT}{\sqrt{2} \pi d^{2}N_{A}P}    (1)

Where:

\lambda=0.2\mu m=0.2(10)^{-6}m

R=8.3145J/mol.K is referred to as the Universal gas constant

T=0\°C=273.115K represents the absolute standard temperature

d denotes the diameter of helium atoms

N_{A}=6.0221(10)^{23}/mol symbolizes Avogadro's number

P=1atm=101.3kPa=101.3(10)^{3}Pa=101.3(10)^{3}J/m^{3} indicates absolute standard pressure

<pFrom this, we can solve for d using (1), aiming to determine the radius r of the helium atom:

d=\sqrt{\frac{RT}{\sqrt{2}\pi\lambda N_{A}P}}    (2)

d=\sqrt{\frac{(8.3145J/mol.K)(273.115K)}{\sqrt{2}\pi(0.2(10)^{-6}m)(6.0221(10)^{23}/mol)(101.3(10)^{3}J/m^{3})}}    (3)

d=2.0467(10)^{-10}m    (4)

If the radius equals half of that diameter:

r=\frac{d}{2}  (5)

Eventually:

r=\frac{2.0467(10)^{-10}m}{2}  (6)

r=1.0233(10)^{-10}m  (7)

Nonetheless, we were tasked with finding this radius in nanometers. Knowing 1nm=(10)^{-9}m:

r=1.0233(10)^{-10}m.\frac{1nm}{(10)^{-9}m}=0.10233nm  (8)

Ultimately:

r=0.10233nm Represents the radius of the helium atom in nanometers.

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where µmg represents the friction experienced by the larger block from contact with the smaller block, µ is the static friction coefficient between both blocks, and A indicates the acceleration of the block;

• the net vertical force on the larger block is

4mg - 3mg - mg = 0

where 4mg denotes the magnitude of the normal force exerted by the surface on the combined mass of both blocks, 3mg corresponds to the weight of the larger block, and mg indicates the weight of the smaller block;

• the net horizontal force acting on the smaller block is

µmg = ma

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mg - mg = 0

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(You should be able to create your own free-body diagrams based on the forces discussed.)

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Answer:

Q = 12.5 kJ

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The formula used to compute heat is:

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Q: heat (J or kJ)

H°: enthalpy of reaction (kJ/mol)

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Now, as noted in the comments, the question lacks completeness, here is the part that is missing:

Given:

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2A + B -------> A2B   H°1 = -25 kJ/mol

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When we add these equations, one A2B cancels out with one A2B from reaction 2, thus, we have:

2A + B + 2A2B -------> 2AB + A2

So, for the enthalpy, the values are summed:

H°3 = -25 + 35 = 10 kJ/mol

Now we can calculate the heat:

Q = 10 * 2.5 = 25 kJ

However, as we have 2A in the reaction, it does not maintain a 1:1 mole ratio, instead, it is 1:2, which requires us to adjust; thus:

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Un tren parte de la ciudad A, a las 8 h. con una velocidad de 50 km/h, para llegar a la ciudad B a las 10 h. Allí permanece dura
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Response:

AB = 100 km; BC = 80 km; AC = 180 km

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Duration = 10:00 - 8:00 = 2.00 hours

(b) Distance

Distance = speed × time = 50 km/h × 2.00 h = 100 km

2. Distance from B to C

Distance = 80 km/h × 1 h = 80 km

3. Summary of Distances

AB = 100 km

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4. Time of Arrival

Departure from A = 08:00

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Answer:

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y=7.39\ m

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The height of a projectile can be calculated using

\displaystyle y=y_o+V_{oy}t-\frac{gt^2}{2}

where y_o represents the initial height from ground level, v_{oy} is the vertical component of the initial velocity, and t is the elapsed time.

The vertical speed component is expressed as

v_y=v_{oy}-gt

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The peak height is attained when v_y=0, which allows us to compute the time to reach that height.

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\displaystyle y=y_o+V_{oy}t-\frac{gt^2}{2}

\displaystyle y=1.5+(11.29)(1.505)-\frac{9.8(1.505)^2}{2}

\displaystyle y=1.5\ m+16,991\ m-11.098\ m

y=7.39\ m

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