Answer:
The mass percent of sulfur is 9.98%.
Explanation:
<em>The percentage of sulfur in coal can be determined by burning a sample of the solid and passing the resulting sulfur dioxide gas into a solution of hydrogen peroxide, which oxidizes it to sulfuric acid, and then titrating the acid.</em>
The corresponding balanced equations are:
S + O₂ ⇄ SO₂ [1]
SO₂ + H₂O₂ ⇄ H₂SO₄ [2]
H₂SO₄ + 2 NaOH ⇄ Na₂SO₄ + 2 H₂O [3]
First, we have to calculate how many moles of NaOH we have.
n = 0.114 mol/L × 0.441 L = 0.0502 mol
Then, we will use the following relations:
- According to [3], 2 moles of NaOH react with 1 mole of H₂SO₄
- According to [2], 1 mole of H₂SO₄ is produced per mole of SO₂
- According to [1], 1 mole of SO₂ is produced per mole of S
- The molar mass of S is 32.0 g/mol
Then, for 0.0502 moles of NaOH:
If there are 0.803 g of S in an 8.05 g sample, the mass percent of sulfur is:
Aluminum foil on door knobs when we want to paint a door to avoid paint stains
<h3>
Aluminum foil Usage</h3>
Aluminium is an element of the periodic table with an atomic number 13.
Now, When painting alone, aluminum foil is used in wrapping doorknobs, and this practice is done to keep paint off.
The usage aluminum foil is an efficient way of keeping away paint from touching door knob
More on Elements
brainly.com/question/2143004
Answer:
The bond between XY is Covalent
Explanation:
Types of Bonds can be predicted by either identifying the two bonding elements or by calculating the difference in electronegativity.
The two atoms bonded to each other can be both metals, non-metals or one metal and the other non-metal. If both are metals then we can say that the bond is metallic. If both are non-metals then we can say that the bond is nonpolar and covalent. If one is metal and the other is non-metal then the bond between them will be ionic.
Secondly,
If, Electronegativity difference is,
Less than 0.4 then it is Non Polar Covalent Bonding
Between 0.4 and 1.7 then it is Polar Covalent Bonding
Greater than 1.7 then it is Ionic Bonding
As, the element X and Y have the electronegativity difference of 1.2 (which is less than 1.7 and greater than 0.4) therefore, we can say that the bond between them is covalent and it is polar in nature.
You need a list of elements to compare.
The procedure is to wirte the electron configuration and compare the number of electrons in the valence electron shell.
I will work with this list, to show you the procedure
(1) tin
(2) sulfur
(3) arsenic
(4) fluorine
element atomic number number of abbreviated electron
electrons configuration
tin 50 50 [Kr] 5s^2 4d^10 5p2
sulfur 16 16 [Ne] 3s^2 3p^4
arsenic 33 33 [Ar] 4s^2 3d^10 4p^3
fluorine 9 9 [He] 2s^2 2p^5
The valence electrons are those in the last shell.
So, fluorine has 2 + 5 = 7 valence electrons, while tin has 2 + 2 = 4, sulfur has 2 + 4 = 6 and aersenic has 2 + 3 = 5.
Therefore, the answer is fluorine.
Answer:
b
Explanation:
A pure substance has a constant composition and cannot be separated into simpler substances by physical means. There are two types of pure substances: elements and compounds.