What is the pH of a .000243 M solution of potassium hydroxide solution?
2 answers:
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PH is defined as the negative log of Hydrogen ion concentration. Mathematically we can write this as:
![pH=-log[H^{+}]=-log[H_{3}O]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%7B%2B%7D%5D%3D-log%5BH_%7B3%7DO%5D%20%20)
We are given the concentration of
. Using the value in formula, we get:
![pH=-log[1.8*10^{-4}]=3.745](https://tex.z-dn.net/?f=pH%3D-log%5B1.8%2A10%5E%7B-4%7D%5D%3D3.745%20)
Therefore, the pH of the solution will be 3.745
We are given the concentration of
Therefore, the pH of the solution will be 3.745
Answer:
Explanation:
When water changes from ice (solid) to water (liquid), it is melting or fusion. Therefore, we can use the following formula to find energy:
where <em>q</em> is the energy, <em>m </em>is the mass, and <em>Hf</em> is the heat of fusion.
1. Define Values
The mass is 150 grams. The heat of fusion for water is 334 Joules per gram.
2. Calculate Energy
Substitute the values into the formula.
Multiply. Note that the grams (g) will cancel each other out and leave Joules as our units.
3. Convert Units
We found the answer in joules, but the question asks for kilojoules, so we must convert.
There are 1000 Joules in 1 kilojoule. Therefore, we can divide the joules calculated by 1000.
<u>50.1 kilojoules </u>are needed to change 150 grams of ice to water.