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Alina [70]
2 years ago
3

A sample of gold (Au) has a mass of 72.04 g. A) Calculate the number of moles of gold (Au) in the sample. Show your work please

Chemistry
1 answer:
Nikitich [7]2 years ago
5 0

Answer:

A.  Number of  moles, n = Reacting mass / Molecular mass

                                 n = 72.04/ 196.966

                                 n = 0.366 mole

Hence, the number of moles of gold (Au) in the sample is 0.366 mole

B. the number of atoms of gold (Au) in the sample is expressed as

                                  = 0.366 * 6.03*∧1023

                                   = 2.20698E35 atoms

Explanation:

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Bismuth(III) sulfate is an ionic compound formed from Bi3+ and SO42-. What is the correct way to represent the formula?
Hitman42 [59]

Answer:

Bi2(SO4)3

Explanation:

Bismuth(iii) sulfate is an ionic compound therefore, their is transfer of electron. Ionic compound has both cations and anions. The cations is positively charged ion while the anions is negatively charged ions. The cations loses electron to become positively charged while the anions gains electron to become negatively charged.

From the compound above, Bismuth(iii) sulfate the cations will be Bismuth ion which loses 3 electrons. The anions is the sulfate ion (S04)2- with a -2 charge.

The chemical formula can be computed from the charge configuration as follows

Bi3+  and (SO4)2-

cross multiply the charges living the sign behind to get the chemical formula

Bi2(SO4)3

Note the final chemical formula, the numbers are sub scripted

4 0
2 years ago
Two electrons in an atom are separated by 1.5 ✕ 10-10 m, the typical size of an atom. what is the electric force between them?
densk [106]
Given two electrons with charge of 1.5x10^-10 m 

The electostatic force between them is determined by this formula: 

F = kq1q2/r^2
   
where 

k = 9x10^9
q1 = q2 = 1.5x10^-10
r = 2.82x10^-15

F = 9x10^9 * (1.5x10^-10)^2 / 2.82x10^-15
   = 71808.51
4 0
2 years ago
Read 2 more answers
Find the age t of a sample, if the total mass of carbon in the sample is mc, the activity of the sample is a, the current ratio
kkurt [141]
should be 7.57*10^3 years
4 0
2 years ago
How many moles of FeS2 are required to produce 32g of SO2?
nirvana33 [79]

Answer:

<u>So, the right answer is</u>

No. of moles of FeS₂ = 0.25 mole

Explanation:

From the balanced

4 FeS2 + 11 O2 → 2 Fe2O3 + 8 SO2

it is clear that 4 mol  FeS₂ react with O₂ to give Fe₂O₃ and 8 mol of SO₂

First, we have to convert mass of SO₂ into No. of moles as following:

SO₂ has molar mass = 64 g/mol

No. of moles of SO₂ = (mass / molar mass) = (32 g / 64 g/mol) = 0.5 mol

we know that  

4 mol  FeS₂  gives→ 8 mol of SO₂

1 mol  FeS₂  gives→ 2 mol of SO₂

??? mol  FeS₂  gives→ 0.5 mol of SO₂

No. of moles of FeS₂ = (0.5 mol * 1 mol ) / 2 mol = 0.25 mol

<u>So, the right answer is</u>

No. of moles of FeS₂ = 0.25 mol

7 0
2 years ago
The intrinsic solubility of sulfathiazole, an old antimicrobial, is 0.002 mol/l. it is a weak acid and its pka is 7.12. what is
lys-0071 [83]

The formula we will use is:

pH = 0.5 (pKa – log C)

where C is the concentration of sulfathiazole in molarity or mol / L

Since all values are given, we can compute directly for pH:

 

pH = 0.5 (7.12 – log 0.002)

<span>pH = 4.91</span>

4 0
2 years ago
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