Answer: (3) molecules have different molecular structures.
Explanation:
1) Oxygen (O₂) and ozone (O₃) are allotropes of each other.
2) Allotropes are different structural forms of a same element with different structures and properties, when they are in the same state: solid, liquid, gas.
3) The bonds is what define the structure and properties of the substances, so since O₂ has only two bonds and O₃ has three bonds, the properties and behaviors of the element are different.
4) Other example of allotropes are graphite and diamond: two different forms of carbon. Both, graphite and diamond are formed only by carbon atoms, but they are bonded differently so, as you know, diamond and graphite have different properties: graphite is very soft while diamond is one of the hardest known substances.
Answer:
Mass = 279.23 g
Explanation:
Given data:
Number of moles of Fe₂O₃ = 3 mol
Number of moles of Al = 5 mol
Maximum amount of iron produced by reaction = ?
Solution:
Chemical equation:
Fe₂O₃ + 2Al → Al₂O₃ + 2Fe
Now we will compare the moles of iron with Al and iron oxide.
Fe₂O₃ : Fe
1 : 2
3 : 2×3 = 6 mol
Al : Fe
2 : 2
5 : 5 mol
The number of moles of iron produced by Al are less so Al is limiting reacting and it will limit the amount of iron so maximum number of iron produced are 5 moles.
Mass of iron:
Mass = number of moles × molar mass
Mass = 5 mol × 55.845 g/mol
Mass = 279.23 g
Answer:
62.5 mg
Explanation:
Just multiply the original amount by 1/2 three times:
500 mg x 1/2 x 1/2 x 1/2 = 62.5 mg
Answer:
10.8amu
Explanation:
Given parameters:
Abundance of B - 10 = 20% = 0.2
Abundance of B - 11 = 80% = 0.8
Unknown:
Atomic mass of Boron = ?
Solution:
The atomic mass of Boron can be can be calculated using the expression below;
Atomic mass = (abundance of B - 10 x mass of isotope B - 10 ) +( abundance of B - 11 x mass of isotope B- 11)
Atomic mass = (0.2 x 10) + (0.8 x 11) = 2 + 8.8 = 10.8amu
