Answer:
A solution is made by dissolving 4.87 g of potassium nitrate in water to a final volume of 86.4 mL solution. The weight/weight % or percent by mass of the solute is :
<u>2.67%</u>
Explanation:
Note : Look at the density of potassium nitrate in water if given in the question.
<u><em>You are calculating </em></u><u><em>weight /Volume</em></u><u><em> not weight/weight % or percent by mass of the solute</em></u>
Here the <u>weight/weight % or percent by mass</u> of the solute is asked : So first convert the<u> VOLUME OF SOLUTION into MASS</u>
Density of potassium nitrate in water KNO3 = 2.11 g/mL
![density=\frac{mass}{volume}](https://tex.z-dn.net/?f=density%3D%5Cfrac%7Bmass%7D%7Bvolume%7D)
Density = 2.11 g/mL
Volume of solution = 86.4 mL
![2.11=\frac{mass}{86.4}](https://tex.z-dn.net/?f=2.11%3D%5Cfrac%7Bmass%7D%7B86.4%7D)
![mass = 2.11\times 86.4](https://tex.z-dn.net/?f=mass%20%3D%202.11%5Ctimes%2086.4)
![mass=182.3grams](https://tex.z-dn.net/?f=mass%3D182.3grams)
Mass of Solute = 4.87 g
Mass of Solution = 183.2 g
w/w% of the solute =
![= \frac{mass\ of\ solute}{mass\ of\ solution}\times 100](https://tex.z-dn.net/?f=%3D%20%5Cfrac%7Bmass%5C%20of%5C%20solute%7D%7Bmass%5C%20of%5C%20solution%7D%5Ctimes%20100)
![=\frac{4.87}{183.2}\times 100](https://tex.z-dn.net/?f=%3D%5Cfrac%7B4.87%7D%7B183.2%7D%5Ctimes%20100)
w/w%=2.67%
Answer:
Einstein realized that the energy in electrons was caused by the frequency of light and not the intensity of light. This made him realize that he needed to explain the photoelectric effect.
Explanation:
Einstein realized that the photoelectric effect was a system that should be studied and explained in more depth, when he saw how the energy of electrons behaved in the presence of light. He saw that this energy depends entirely on the frequency of light and not on the intensity of light. From this observation, he realized that the photoelectric effect was essential for the production of an electric energy system, through light energy, such as solar energy.
It is important to note that the photoelectric effect refers to the ejection of electrons on a light surface that comes into contact with a light source.
Answer:
Iodine 131 is an unstable/radioactive isotope of iodine and a normal atom of iodine is stable.
Explanation:
The formula for phosphorus is P4