Answer:
The molarity of urea in this solution is 6.39 M.
Explanation:
Molarity (M) is <em>the number of moles of solute in 1 L of solution</em>; that is
To calculate the molality, we need to know the number of moles of urea and the volume of solution in liters. We assume 100 grams of solution.
Our first step is to calculate the moles of urea in 100 grams of the solution,
using the molar mass a conversion factor. The total moles of 100g of a 37.2 percent by mass solution is
60.06 g/mol ÷ 37.2 g = 0.619 mol
Now we need to calculate the volume of 100 grams of solution, and we use density as a conversion factor.
1.032 g/mL ÷ 100 g = 96.9 mL
This solution contains 0.619 moles of urea in 96.9 mL of solution. To express it in molarity, we need to calculate the moles present in 1000 mL (1 L) of the solution.
0.619 mol/96.9 mL × 1000 mL= 6.39 M
Therefore, the molarity of the solution is 6.39 M.
Answer: Substance is Mercury (Hg)
number of protons = 80
number of electrons = 80
Explanation:
Atomic number which is symbolized by "Z" is the number of protons in nucleus of an atom.
Hence,
number of protons = atomic number = 80
- By knowing atomic number, we can find the element by using periodic table. Since the atomic number 80, the element is Mercury (Hg).
If the substance is in its neutral state, which means there is no charge on it, then the number of protons equals to the number of electrons of that element.
Hence,
number of electrons = number of protons = 80
The given statement, some type of path is necessary to join both half-cells in order for electron flow to occur, is true.
Explanation:
Flow of electrons is possible with the help of a conducting medium like metal wire.
A laboratory device which helps in completion of oxidation and reduction-half reactions of a galvanic or voltaic cell is known as salt bridge. Basically, this salt bridge helps in the flow of electrons from anode to cathode and vice-versa.
If salt bridge is not present in an electrochemical cell, the electron neutrality will not be maintained and hence, flow of electrons will not take place.
Thus, we can conclude that the statement some type of path is necessary to join both half-cells in order for electron flow to occur, is true.
Answer:
The blood circulatory system (cardiovascular system) delivers nutrients and oxygen to all cells in the body. It consists of the heart and the blood vessels running through the entire body. The arteries carry blood away from the heart; the veins carry it back to the heart.
Explanation:
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Solution:
To convert Celsius to Fahrenheit, the formula to be used is (C * 9/5) + 32
So in our given, 28.7 degrees Celsius:
Farenheit = (28.7 * 9/5) + 32
= 51.66 + 32
= 83.66 degrees Fahrenheit
Next, 35.5 degrees Celsius:
Farenheit = (35.5 * 9/5) + 32
= 63.9 + 32
= 95.9 degrees Fahrenheit
So in Fahrenheit, the range would be 83.66 – 95.9 degrees Fahrenheit.
