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2 years ago

A compound is found to contain 23.3% magnesium, 30.7% sulfur and 46.0% oxygen. What is the empirical formula of this compound?

Chemistry

2 answers:

Nesterboy [21]2 years ago

6 0

Answer:

MgSO_3

Explanation:

As is standard for these sorts of questions, we assume 100 g of substance, and use the percentage elemental compositions to calculate an empirical formula.

"Magnesium" = (23.3*g)/(24.31*g*mol^-1) = 0.958*mol

"Sulfur" = (30.7*g)/(32.06*g*mol^-1) = 0.958*mol

"Oxygen" = (46.0*g)/(15.999*g*mol^-1) = 2.86*mol

We divide thru by the smallest molar quantity (0.958*mol) to get and empirical formula of MgSO_3, magnesium sulfite.

Ordinarily you would not be given the percentage of oxygen by mass. You would be given the percentages of the metal and sulfur, and would have to assume that the balance was oxygen.

Hope this helps!

-Much love, Makayla

SVEN [57.7K]2 years ago

3 0

MgSO_3 is the answer

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Type the correct answer in the box. Express your answer to three significant figures.

satela [25.4K]

Answer:

The partial pressure of argon in the jar is 0.944 kilopascal.

Explanation:

Step 1: Data given

Volume of the jar of air = 25.0 L

Number of moles argon = 0.0104 moles

Temperature = 273 K

Step 2: Calculate the pressure of argon with the ideal gas law

p*V = nRT

p = (nRT)/V

⇒ with n = the number of moles of argon = 0.0104 moles

⇒ with R = the gas constant = 0.0821 L*atm/mol*K

⇒ with T = the temperature = 273 K

⇒ with V = the volume of the jar = 25.0 L

p = (0.0104 * 0.0821 * 273)/25.0

p = 0.00932 atm

1 atm =101.3 kPa

0.00932 atm = 101.3 * 0.00932 = 0.944 kPa

The partial pressure of argon in the jar is 0.944 kilopascal.

5 0

2 years ago

An atom of beryllium (m = 8.00 u) splits into two atoms of helium (m = 4.00 u) with the release of 92.2 kev of energy. if the or

galben [10]

The kinetic energy of the products is equal to the energy liberated which is 92.2 keV. But let's convert the unit keV to Joules. keV is kiloelectro volt. The conversion that we need is: 1.602×10⁻¹⁹ <span>joule = 1 eV

Kinetic energy = 92.2 keV*(1,000 eV/1 keV)*(</span>1.602×10⁻¹⁹ joule/1 eV) = 5.76×10²³ Joules

From kinetic energy, we can calculate the velocity of each He atom:
KE = 1/2*mv²
5.76×10²³ Joules = 1/2*(4)(v²)
v = 5.367×10¹¹ m/s

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2 years ago

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Pure platinum is too soft to be used in jewelry because it scratches easily. To increase the hardness so that it can be used in

Zina [86]

Answer:

percentage mass of platinum in the alloy ≈ 90.60 %

Explanation:

The alloy is 8.528 g sample of an alloy containing platinum and cobalt . The alloy react with excess nitric acid to form cobalt(ii) nitrate . Platinum is resistant to acid so it will definitely not react with the acid only the cobalt metal in the alloy will react with the acid.

The chemical reaction can be represented as follows:

Co (s) + HNO₃ (aq) → Co(NO₃)₂ (aq) + NO₂ (l) + H₂O (l)

The balanced equation

Co (s) + 4HNO₃ (aq) → Co(NO₃)₂(aq) + 2NO₂ (l) + 2H₂O (l)

Cobalt is the limiting reactant

atomic mass of cobalt = 58.933 g/mol

Molar mass of Co(NO₃)₂ = 58.933 + 14 × 2 + 16 × 6 = 58.933 + 28 + 96 = 182.933 g

58.933 g of cobalt produce 182.933 g of Co(NO₃)₂

? gram of cobalt will produce 2.49 g of Co(NO₃)₂

cross multiply

grams of cobalt that will react = (58.933 × 2.49)/182.933

grams of cobalt that will react = 146.74317000/182.933

grams of cobalt that will react= 0.8021689362 g

grams of cobalt that will react = 0.802 g

mass of platinum in the alloy = 8.528 g - 0.802 g = 7.726 g

percentage mass of platinum in the alloy = 7.726/8.528 × 100 = 772.600/8.528 = 90 .595 %

percentage mass of platinum in the alloy ≈ 90.60 %

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2 years ago

The successive ionization energies of a certain element are I1= 577.9 kJ/mol, I2 = 1820 kJ/mol, I3= 2750 kJ/mol, I4 = 11,600 kJ/

Maksim231197 [3]

Answer:

Aluminium

Explanation:

Ionization energy is the amount of energy needed to remove an electron from a gaseous atom to form a gaseous ion.

The difference between the third and fourth ionization energies is great. This indicates a group III element which is in the third period.

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2 years ago

Which statement best describes what happens when oil and water are stirred together? (1 point)

Charra [1.4K]

When oil and water are stirred together, water molecules will attract each other electrically, but they will not attract oil molecules, causing separation.

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Therefore, when oil and water are stirred together, water molecules will attract each other electrically, but they will not attract oil molecules, causing separation.

Learn more: brainly.com/question/7484286?referrer=searchResults

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1 year ago

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