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.
Extensive properties, such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present.
Answer:
mm = 1043.33 g/mol
Explanation:
osmotic pressure (π):
∴ π = 17.8 torr = 0.0234 atm
∴ Cb: solute concentration
∴ T = 25°C = 298 K
∴ R = 0.082 atm.L/K.mol
⇒ Cb = π/RT
⇒ Cb = (0.0234 atm)/((0.082 atm.L/K.mol)(298 K))
⇒ Cb = 9.585 E-4 mol/L
molar mass (mm):
⇒ mm = (1.00 g/L)(L/9.585 E-4 mol)
⇒ mm = 1043.33 g/mol
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Mineral because its not a rock
