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.
Any change in which the composition of material does not change that is it retains its identity but changes its state or form is known as a physical change.
The properties of metal to draw them into wires is known as ductility. When a copper is drawn into wire the only change that occurs is change in its shape and size no change will take place into its composition that is the wires are still possessing the properties of copper metal. Thus, a physical change takes place when copper is drawn into wire.
When you plug in an electrical heater, it turns the electrical energy into radiant energy.<span />
Correct, Was that a question.
