Answer:
Six electrons are transferred in the formation of Al₂O₃.
Explanation:
Aluminium metal and Oxygen react to form Al₂O₃ as,
2 Al + 3/2 O₂ → Al₂O₃
Oxidation number of Al on left hand side is zero, while than on right hand side in Al₂O₃ is +3. Means it has lost 3 electrons per one atom and six electrons per two atoms. Also, the oxidation number of O at left hand side in O₂ is zero, while that in Al₂O₃ it is -2 per atom and -6 per 3 atoms.
So, two Al atoms have lost 6 electrons and 3 O atoms have gained six electrons.
Answer:
1.88 x 10²³molecules of H₂O
Explanation:
Given parameters:
Mass of H₂O = 5.609g
Unknown:
Number of molecules of H₂O = ?
Solution:
To solve this problem, we need to find the number of moles of given compound first.
Number of moles =
Molar mass of H₂O = 2(1) + 16 = 18g/mol
Number of moles = = 0.31mole
From mole concept;
1 mole of a substance contains 6.02 x 10²³molecules
0.31 mole of H₂O will therefore contain 0.31 x 6.02 x 10²³molecules
= 1.88 x 10²³molecules of H₂O
Molarity is defined as the number of moles of solute in 1 L of solution
molarity of solution to be prepared is 0.85 M
this means that there should be 0.85 mol of KBr in 1 L of solution
if 1 L contains - 0.85 mol
then 25.0 mL should contain - 0.85 mol / 1000 mL x 25.0 mL = 0.0213 mol
mass of KBr - 0.0213 mol x 119 g/mol = 2.53 g
mass of KBr that should be dissolved in 25.0 mL is 2.53 g
0.88qt
Explanation:
Given parameters:
Density of ebony wood = 1.174g/ml
Mass of wood = 2.1549lb
Unknown:
Volume of the wood in quarts = ?
Solution:
Density is defined as the mass per unit volume of a substance.
Mass is the quantity of matter the wood contains.
Volume is the space it occupies.
To solve this problem, convert the mass form pounds into grams and plug into the density equation to find volume.
Then convert the volume from mL to quarts.
Density =
Volume =
1 pound = 453.592g
2.1549 lb = 2.1549 x 453.592 = 977.5g
Volume = = 832.6mL
1 quart = 946.353mL
Therefore 832.6mL x = 0.88qt
learn more:
Density brainly.com/question/8441651
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