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3 years ago

You need 2.5 moles of aluminum for an experiment. How many atoms of aluminum is this?

Chemistry

1 answer:

emmainna [20.7K]3 years ago

3 0

Answer:

1.505×10^24 atoms

Explanation:

1mole=6.02×10^23 atoms

2.5moles=?

(crossmultiply)

2.5×6.02×10^23 ÷1

=1.505×10^24 atoms

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Suppose that you place exactly 100 bacteria into a flask containing nutrients for the bacteria and that you find the following d

tresset_1 [31]

Answer:

The order of the production of bacteria is 1.

12,787 bacteria will be present after 112 min.

$0.04331 min^{-1}$ is the rate constant for the process.

Explanation:

Rate of formation of bacteria when there 100 bacteria: R

Rate of formation of bacteria when there 200 bacteria: R' =2R

Rate of formation of bacteria is directly proportional to the number of bacteria:

$\frac{R}{R'}=\frac{k[200]^x}{k[400]^x}$

$\frac{R}{2R}=(\frac{200}{400})^x$

x = 1

The order of the production of bacteria is 1.

The half life of the process = $t_{1/2}=16 minutes$

Rate constant of the process = k

For first order process k is only dependent on half life:

$k=\frac{0.693}{t_{1/2}}$

$k=\frac{0.693}{16 min}=0.04331 min^{-1}$

For the first order process the increment numbers is given ;

$N=N_o\times e^{kt}$

Where:

$N_o$ = Initial population

N = Population after time t.

We have ;

$N_o=100$

t = 112 minutes

$N=100\times e^{0.04331 min^{-1}\times 112 min}$

$N = 12,786.82\approx 12,787$

12,787 bacteria will be present after 112 min.

$0.04331 min^{-1}$ is the rate constant for the process.

5 0

3 years ago

Calculate the wavelength, in nanometers, of the light emitted by a hydrogen atom when its electron fallsfrom the n = 7 to the n

Helga [31]

Answer:

λ=2167.6 nm

The wavelength of light emitted is 2167.6 nm.

Explanation:

We recall that Eₙ= $\frac{-2.18*10^{-18} J}{n^{2} }$

since there was transition from n7 to n=4 we will first calculate the change in the energy i.e ΔE

ΔE=E₄-E₇

ΔE= $-2.18*10^{-18} J(\frac{1}{4^{2} } -\frac{1}{7^{2} } )$

ΔE=-9.1760*10^-20 J

Now:

|ΔE|=Energy of photon=h*v=h*c/λ

λ=h*c/|ΔE|

λ= $\frac{6.63*10^{-34}J.s*3.00*10^{8}m/s }{9.1760*10^{-20} J }$

λ=2.1676*10^-6 m

λ=2167.6*10^-9 m

λ=2167.6 nm

The wavelength of light emitted is 2167.6 nm.

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3 years ago

Use the formula: PV=nRT<br><br> If P=12, V=22.4, R=.0821 and T=100, then what would n=?

Lina20 [59]

$PV=nRT \\ (12)(22.4)=n(.0821)(100) \\ 268.8=8.21n \\ 268.8/8.21=8.21n/8.21 \\ n=32.74$
n ≈ 32.74
Hope this helps!

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3 years ago

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Liula [17]

Answer:

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3 years ago

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Answer:

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3 years ago

You need 2.5 moles of aluminum for an experiment. How many atoms of aluminum is this?​

You need 2.5 moles of aluminum for an experiment. How many atoms of aluminum is this?