Answer:
46.40 g.
Explanation:
- It is a stichiometric problem.
- The balanced equation of the reaction: 4K + O₂ → 2K₂O.
- It is clear that 4.0 moles of K reacts with 1.0 mole of oxygen produces 2.0 moles of K₂O.
- We should convert the mass of K (38.5 g) into moles using the relation:
<em>n = mass / molar mass,</em>
n = (38.5 g) / (39.098 g/mol) = 0.985 mole.
<em>Using cross multiplication:</em>
4.0 moles of K produces → 2.0 moles of K₂O, from the stichiometry.
0.985 mole of K produces → ??? moles of K₂O.
∴ The number of moles of K₂O produced = (0.985 mole) (2.0 mole) / (4.0 mole) = 0.4925 mole ≅ 0.5 mole.
- Now, we can get the mass of K₂O:
∴ mass = n x molar mass = (0.5 mole) (94.2 g/mol) = 46.40 g.
<span> C.The results of the Michelson-Morley experiment did not fit the theory of the luminiferous ether, so the theory had to be rejected. </span>
In chemistry, the molar mass M is a physical property defined as the mass of a given substance (chemical element or chemical compound) divided by its amount of substance. The base SI unit for molar mass is kg/mol. However, for historical reasons, molar masses are almost always expressed in g/mol.
Hope this helped!
Good luck :p
~Emmy <3
Answer:
Th is the symbol for element Thorium.
Mg is magnesium while Mg 2+ is magnesium Ion. Judging from periodic trends, atomic radius is one half the distance between the atoms of two covalently bonded atoms. It decreases as elevtrons are added to valence shells. That means, across the period it increases and down the group it decreases. Making Mg2+ smaller.
Electronegativity is the energy needed to take an electron in the gaseous state. Florine is more electron negative that lithium. It increases across the period and decreases down the group. Except in the Noble group.
Explanation:
