Answer:
12.99
Explanation:
<em>A chemist dissolves 716. mg of pure potassium hydroxide in enough water to make up 130. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Be sure your answer has the correct number of significant digits.</em>
Step 1: Given data
- Mass of KOH: 716. mg (0.716 g)
- Volume of the solution: 130. mL (0.130 L)
Step 2: Calculate the moles corresponding to 0.716 g of KOH
The molar mass of KOH is 56.11 g/mol.
0.716 g × 1 mol/56.11 g = 0.0128 mol
Step 3: Calculate the molar concentration of KOH
[KOH] = 0.0128 mol/0.130 L = 0.0985 M
Step 4: Write the ionization reaction of KOH
KOH(aq) ⇒ K⁺(aq) + OH⁻(aq)
The molar ratio of KOH to OH⁻is 1:1. Then, [OH⁻] = 0.0985 M
Step 5: Calculate the pOH
We will use the following expression.
pOH = -log [OH⁻] = -log 0.0985 = 1.01
Step 6: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - pOH = 14 -1.01 = 12.99
Answer: kinetic energy
Explanation: kenitic energey is answer1 Awnser2 potentialand 3 is friction
Answer:
I. The balloon has a volume of 22.4L
III. The balloon contains 6.022x10^23 molecules.
Explanation:
At stp, it has been proven that 1mole of a gas occupy 22.4L.
Therefore, option (i) is correct.
The molar mass N2 = 14.01 x 2 = 28.02g/mol
Number of mole of N2 = 1 mole
Mass of N2 =..?
Mass = mole x molar Mass
Mass of N2 = 1 x 28.02 = 28.02g.
The mass content of the balloon is 28.02g, therefore, option (ii) is wrong.
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02x10^23 molecules. This implies that 1 mole of N2 also contains 6.02x10^23 molecules
Therefore, option (iii) is correct.
The correct options to the question are:
Option i and option iii
Answer:
Scientific Method.
Explanation:
A scientific method is basically a method or a process when you conduct an experiment. Normally, the process goes like this:
1. You make like a question or something that you want to investigate, it's like the aim of the experiment.
2. You make an experiment and a hypothesis. A hypothesis is basically a guess on how the results of the experiment would turn out. You don't have to be correct for the hypothesis since there is no right or wrong answer.
3. Conduct the experiment. I don't think this needs a detailed explanation since experiments vary from one another.
4. Collect results. The data you collect come in different ways based on your experiment, but it is crucial you get data so that you can answer your question in 1.
5. Make inferences. You can't directly get a conclusion or answer from the results, so inferences are needed.
6. Craft a conclusion or answer. This is the final step when conducting an experiment and the part where you have the answer you needed when you conducted the experiment :)
Answer:
Three chemical elements: hydrogen, oxygen, and helium.
The difference between metals and metalloids is: metalloids have properties in between those of the metals and non-metals and are semiconductors.
The periodic table is organized by the elemts atomic number, it goes from the element with the lowest atomic number (which is hydrogen) to the element with the highest atomic number (oganesson)
Explanation:
Hope this helps :)
