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.
Answer:
The water potential of a solution of 0.15 M sucrose solution is -3.406 bar.
Explanation:
Water potential = Pressure potential + solute potential
We have :
C = 0.15 M, T = 273.15 K
i = 1
The water potential of a solution of 0.15 m sucrose= 
(At standard temperature)
The water potential of a solution of 0.15 M sucrose solution is -3.406 bar.
Incomplete question. Full question reads;
Darwin developed the theory of evolution to explain why there are so many different kinds of living things. He could easily observe that offspring of any animals were slightly different from their parents and that this could allow for big changes over thousands of years. He did not know that genes caused the differences. Genes are now very important in the modern theory of evolution.
What most likely led to a change in the widely accepted theory of evolution?
Answer:
<u>new experiments involving genes and evolution </u>
<u>Explanation:</u>
Indeed, the original theory of evolution has experienced several changes in its acceptance because of its imperfect and wrong assumptions not based on generally acceptable scientific facts,
Hence, new experiments involving genes and evolution has led to a change (disagreements and few agreements) in the widely accepted theory of evolution.
Explanation:
Higher the frequency smaller will be the wavelength. Higher frequency have shorter wavelength and lower frequency waves have larger wavelength. Also, Beats are formed by the superposition of two waves with slightly different frequencies but with similar amplitudes. In time, waves switch between constructive interference and disruptive interference, giving the resultant wave a time-varying amplitude.
