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3 years ago

For the mineral torbernite, Cu(UO2)2(PO4)2⋅8H2O, determine the total number of atoms in one formula unit

Chemistry

1 answer:

ASHA 777 [7]3 years ago

6 0

Answer:

$2.47x10^{25}atoms$

Explanation:

Hello,

In this case, since the mineral torbernite has one copper atom, two uranium atoms, twenty oxygen atoms (2x2+4x2+8), two phosphorous atoms and sixteen hydrogen atoms (12x2) and therefore forty one in total, by using the Avogadro's number one is able to compute the total number of atoms in one formula unit or one mole:

$Atoms=1molCu(UO_2)_2(PO_4)_2\dot \ 8H_2O*\frac{41mol\ of \ atoms}{1molCu(UO_2)_2(PO_4)_2\dot \ 8H_2O}*\frac{6.022x10^{23}atoms}{1mol\ of \ atoms} \\\\=2.47x10^{25}atoms$

Best regards.

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Answer:0

Explanation:

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3 years ago

Calculate the concentration of all species in a 0.165 m solution of h2co3.

xxMikexx [17]

(1) H2CO3 + H2O --> HCO3- + H3O+ [Ka = 4.5E-7]

(2) HCO3- + H2O --> CO32- + H3O+ [Ka = 4.7E-11]

Observe that the two Ka values differ from each other drastically. This will mean that in terms of pH, ONLY THE FIRST IONIZATION WILL AFFECT pH.

(1) H2CO3 + H2O --> HCO3- + H3O+ [Ka = 4.5E-7]

I.....0.165M..................0..........

C......-x......................+x........

E....0.165-x.................x...........

4.5E-7 = x^2/(0.165-x) <-- use the appoximation rule because Ka is very small

2.72E-4 = x

Thus, from equation (1), we see that the [H3O+] = 2.72E-4M, [H2CO3] = 0.165M, and [HCO3-]= 2.72E-4M. Note that THIS step will determine the pH of the polyprotic acid

To calculate the last species, just transfer these values the next equation

(2) HCO3- + H2O --> CO32- + H3O+ [Ka = 4.7E-11]

I....2.72E-4..................0..........

4.7E-11 = (x*2.72E-4)/2.72E-4

4.7E-11 = x = [CO32-]

To calculate the OH- from H3O+, just find the pH of H3O+, subtract it from 14 to find the pOH, and find the [OH-] from that.

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3 years ago

Compared with the freezing-point depression of a 0.01 m c6h12o6 solution, the freezing-point depression of a 0.01 m nacl solutio

agasfer [191]

Answer:

Twice as much.

Explanation:

That's because the freezing point depression depends on the total number of solute particles.

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0.01 mol of C₆H₁₂O₆ gives 0.01 mol of solute particles.

NaCl(s) ⟶ Na⁺(aq) + Cl⁻(aq)

1 mol of NaCl gives 0.01 mol of Na⁺(aq) and 0.01 mol of Cl⁻(aq).

That's 0.02 mol of particles, so the freezing point depression of 0.01 mol·L⁻¹ NaCl will be twice that of 0.01 mol·L⁻¹ C₆H₁₂O₆.

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3 years ago

A sodium ion, Na+, with a charge of 1.6×10−19C and a chloride ion, Cl− , with charge of −1.6×10−19C, are separated by a distance

sasho [114]

Answer:

$W\geq 2.1x10^{-19}J$

Explanation:

Due to Coulomb´s law electric force can be described by the formula $F=K\frac{q_{1}.q_{2}}{r^{2}}$ , where K is the Coulomb´s constant ( $9x10^{9} N\frac{m^{2} }{C^{2} }$ ), $q_{1}$ = Charge 1 (Na+ in this case), $q_{2}$ is the charge 2 (Cl-) and r is the distance between both charges.

Work made by a force is W=F.d and total work produced is the change in energy between final and initial state. this is $W=W_{f} -W_{i}$ .

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Given that ri= 1.1nm= $1.1x10^{-9}m$ and rf= infinite distance

$W=(9x10^{9})(1.6x10^{-19})(-1.6x10^{-19})[\frac{1}{\alpha }-\frac{1}{(1.1x10^{-9})}]=2.1x10^{-19}J$

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3 years ago

How much energy is required to convert 100.0 g of water completely to steam?

Brrunno [24]

Answer:

225.6 kJ, assuming the water is already at 100 °C

Explanation:

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Assuming that we are already at 100 °C, we can calculate the heat required for vaporization:

(100.0g)(1000.0g/1 kg)(2256.4 kJ/kg) = 225.6 kJ for 100 grams water.

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3 years ago