chemistry help..?
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best answer ten points.
1: The main products of the incomplete combustion of hydrogen sulfide and oxygen are
hydrogen and sulfur
hydrogen and sulfur dioxide
water and sulfur
water and sulfur dioxide
2: The action of concentrated sulfuric acid on carbohydrates is known as
dehydration
esterification
hydrolysis
oxidation
3: The allotropic form of sulfur produced by heating sulfur to its boiling point and pouring it in cold water is
amorphous
monoclinic
prismatic
rhombic
4: A water solution of hydrogen sulfide is called
hydrosulfuric acid
sulfuric acid
sulfurous acid
thiosulfuric acid
5: SUperphosphate is made by treating calcium phosphate with
calcium hydroxide
hydrochloric acid
phosphoric acid
sulfuric acid
6: Burning sulfur in oxygen results chiefly in the product
SO
SO2
SO3
SO4
7: The gas that is formed when HCl is added to a mixture of iron and sulfur is
chlorine
hydrogen
hydrogen sulfide
sulfur dioxide
8: Copper reacts with hot concentrated H2SO4 to yield
H2
O2
SO2
SO3
9: The tarnish formed on table silver is
Ag2O
Ag2S
Ag2SO4
Ag
10: When sulfur and copper are heated together
copper sulfate is formed
copper sulfide is formed
copper sulfite is formed
sulfurous acid is formed
11: A water solution of sulfur dioxide is called
fuming sulfuric acid
hydrosulfuric acid
sulfuric acid
sulfurous acid
12: Sulfites are salts of
H2S
H2SO2
H2SO3
H2SO4
13: A water solution of hydrogen sulfide is a
strong alkali
weak alkali
strong acid
weak acid
14: The element used in vulcanizing rubber is
hydrogen
potassium
sodium
sulfur
15: Rhombic sulfur is most soluble in
alcohol
carbon disulfide
sodium chloride solution
water
16: The formula of sodium sulfite is
Na2S
Na2SO2
Na2SO3
Na2SO4
17: The anhydride of sulfuric acid is
H2S
H2SO3
SO2
SO3
Filed under: Potassium and Being Sick
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(1) Complete combustion:
H2S(g) + 3/2O2(g) ——–> H2O(g) + SO2(g)
Incomplete combustion:
H2S(g) + 1/2O2(g) ——–> H2O(g) + S(s)
Therefore it produces water and sulfur.
(2) Concentrated sulfuric acid is a very hygroscopic (it strongly absorbs water). For example when it is added on sugar (sucrose) it absorbs the H and O atoms present in sugar in the form of water and black carbon is left (carbon cake):
C12H22O11 ——–> 12C + 11H2O
The process is dehydration.
(3) If very hot molten sulfur is poured in cold water, the sulfur atoms cannot find time to take their places in the crystal lattice and amorphous sulfur (plastic sulfur) forms.
(4) When H2S gas is dissolved in water, hydrosulfuric acid forms, like the formation of hydrochloric acid when hydrogen chloride gas dissolved in water.
H2S(g) ———-> H2S(aq)
(5) Superphosphate is an artifical fertilizer produced by the action of concentrated sulfuric acid on powdered calcium phosphate.
Ca3(PO4)2 + 2H2SO4 ? Ca(H2PO4)2 + 2CaSO4
(6) When sulfur burns, sulfur dioxide gas is obtained.
S(s) + O2(g) ——-> SO2(g)
(7) HCl only reacts with iron in the mixture by giving off hydrogen gas.
Fe(s) + 2HCl(aq) ——-> FeCl2(aq) + H2(g)
(8) Cu is not an active metal like Fe. Therefore, the formation of H2 gas like in (7) is not expected. Because H2SO4 acts on Cu in two steps:
a) Cu(s) + H2SO4(aq) ——-> CuO(s) + H2O(l) + SO2(g)
b) CuO(s) + H2SO4(aq) ——-> CuSO4(aq) + H2O(l)
The gas produced is SO2 (sulfur dioxide)
(9) Silver tarnish is formed because of the action of hydrogen sulfide in air. Therefore the chemical composition of tarnish is Ag2O (silver sulfide).
(10) Cu(s) + S(s) ——-> CuS (copper (II) sulfide)
(11) When sulfur dioxide dissolves in water sulfurous acid, when sulfur trioxide dissolves in water sulfuric acid forms.
SO2(g) + H2O(l) ——> H2SO3 sulfurous acid
SO3(g) + H2O(l) ——> H2SO4 sulfuric acid
(12) The salts of sulfurous acid (H2SO3) are sulfits and the salts of sulfuric acid (H2SO4) are sulfates.
(13) Water solution of H2S as stated in (4) forms an acid. But this acid is a very weak acid.
(14) The element used in vulcanization is sulfur. The process is invented by Charles Goodyear.
(15) Rhombic sulfur is soluble in carbon disulfide (CS2).
(16) Since the salts of sulfurous acid (H2SO3) are sulfits, the formula is Na2SO3.
(17) The anhydride is a substance which produces acid when dissolved in water. As it is stated in (11), SO3 forms sulfuric acid:
SO3(g) + H2O(l) ——> H2SO4 sulfuric acid