Answer: -
81.03 g magnesium oxide is formed when 48.62g of magnesium is reacted with excess oxygen
Explanation: -
Atomic mass of Mg = 24 g
Molar mass of MgO = 24 x 1 + 16 x 1
= 40 g
The balanced chemical equation for this reaction is
2 Mg + O₂ → 2MgO
From the balanced chemical equation we see
2 mol of Mg gives 2 mol of MgO.
2 x 24 g of Mg gives 2 x 40g of MgO.
48.62 g of Mg gives 
x Mg
= 81.03g of MgO
Answer:
0.0833 moles of O₂
Explanation:
Most usual Law to solve this sort of problem, is the Ideal Gases Law
Pressure . Volume = number of moles . R . Temperature
where R is the Ideal Gases Constant → 0.082 L.atm/mol.K
First of all we need to convert the pressure from kPa to atm, because the Units of R
320 kPa . 1 atm / 101.3 kPa = 3.16 atm
Now, you replace data:
3.16 atm . 0.45L = mol . 0.082 L.atm/mol.K . 280K
(3.16 atm . 0.45L) / (0.082 L.atm/mol.K . 280K) = mol
0.0833 moles of O₂
I believe the answer is yes
We have to discuss here whether mole should be considered as a base unit in SI system or not.
The answer is- mole is considered as base unit in SI system.
There are seven base units in the SI system. They are- kilogram (kg) for mass, second (s) for time, kelvin (K) for temperature, ampere (A) for electric current, mole (mol) for the amount of substance, candela (cd) for luminous intensity and meter (m) is for distance.
Mole is defined as the amount of substance that contains as many elementary entities as there are atoms in 0.012 kilogram of carbon-12. One mole contains exactly 6.022 X 10²³ elementary entities.
This number 6.022 X 10²³ is the fixed numerical value which is called Avogadro number which is universally accepted number. Hence mole is also base unit in the SI system.
