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3 years ago

How many moles are in 2.85x 10^23 atoms of silver

Chemistry

1 answer:

Bingel [31]3 years ago

7 0

Answer:

0.473 moles

Explanation:

(2.85x10e23)/(6.02x10e23) = 0.47342

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Q10.An aqueous solution contains 5.00x10-2 mol/L of Ca2+ and 7.00x10-3 mol/L of SO4

romanna [79]

Answer:

The precipitate will form.

Explanation:

Let's write the equilibrium expression for the solubility product of calcium sulfate:

$CaSO_4(s)$ ⇄ $Ca^{2+}(aq)+SO_4^{2-}(aq)$

The solubility product is defined as the product of the free ions raised to the power of their coefficients, in this case:

$K_{sp}=[Ca^{2+}][SO_4^{2-}]=10^{-4.5}$

Our idea is to find the solubility quotient, Q, and compare it to the K value. A precipitate will only form if Q > K. If Q < K, the precipitate won't form. In this case:

$Q_{sp}=[Ca^{2+}][SO_4^{2-}]=5.00\cdot10^{-2} M\cdot7.00\cdot10^{-3} M=3.5\cdot10^{-4}$

Now given the K value of:

$K_{sp}=10^{-4.5}=3.2\cdot10^{-5}$

Notice that:

$Q_{sp}>K_{sp}$

This means the precipitate will form, as we have an excess of free ions and the equilibrium will shift towards the formation of a precipitate to decrease the amount of free ions.

6 0

4 years ago

Using the Bohr model, determine the energy, in joules, necessary to ionize a ground-state hydrogen atom. Show your calculations.

lord [1]

Answer:

The energy required to ionize the ground-state hydrogen atom is 2.18 x 10^-18 J or 13.6 eV.

Explanation:

To find the energy required to ionize ground-state hydrogen atom first we calculate the wavelength of photon required for this operation.

It is given by Bohr's Theory as:

1/λ = Rh (1/n1² - 1/n2²)

where,

λ = wavelength of photon

n1 = initial state = 1 (ground-state of hydrogen)

n2 = final state = ∞ (since, electron goes far away from atom after ionization)

Rh = Rhydberg's Constant = 1.097 x 10^7 /m

Therefore,

1/λ = (1.097 x 10^7 /m)(1/1² - 1/∞²)

λ = 9.115 x 10^-8 m = 91.15 nm

Now, for energy (E) we know that:

E = hc/λ

where,

h = Plank's Constant = 6.625 x 10^-34 J.s

c = speed of light = 3 x 10^8 m/s

Therefore,

E = (6.625 x 10^-34 J.s)(3 x 10^8 m/s)/(9.115 x 10^-8 m)

E = (2.18 x 10^-18 J)(1 eV/1.6 x 10^-19 J)

5 0

4 years ago

How do you convert 42.7L to mL

zimovet [89]

1L=1000 mL,L GOES BOTTOM AND mL GOES TOP,ANSWER SHOULD BE 42700.

4 0

4 years ago

Calcium carbonate, CaCO3(s), the principal compound in limestone, decomposes upon heating to CaO(s) and CO2(g). A sample of CaCO

lorasvet [3.4K]

Answer:

n = 0.01302 moles

Explanation:

Pressure = 1.3 atm

Temperature = 31 °C + 273 = 304 K ( Converting to kelvin temperature)

Number of moles = ?

Volume = 250 mL = 0.250 L

These quantities are related by the equation below;

PV = nRT

n = PV / RT

n = (1.3 * 0.250) / (0.0821 * 304)

n = 0.01302 moles

5 0

3 years ago

The average wind speed, humidity, and temperature of an area over time are factors of A) climate. B) cold fronts. C) biodiversit

viva [34]

Pretty sure it's a.

3 0

3 years ago

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How many moles are in 2.85x 10^23 atoms of silver ​

How many moles are in 2.85x 10^23 atoms of silver