First, find the number of moles of UF6
Avagadro's number = 6.023 x 10^23
Number of moles = 8.0 x 10^26 / Avagadro's number = 8.0 x 10^26 / 6.023 x 10^23 = 1.328 x 10³ moles
Molecular weight of UF6 = Molecular weight of U (238.02891) + Molecular weight of F6 (6 x 18.9984032) = 238.02891 + 113.9904192 = 352.0193292 g/mol
Therefore mass of 8.0 x 10^26 UF6 molecules = 352.0193292 g/mol x 1.328 x 10³ moles = 467.481669 x 10³ grams
What are the answer choices?
<u>Correct Question Format:</u>
Throughout your job search, you’ll find that
A the economy
B education
C salary
is closely related to the career of your choosing. It’s important to take the time to find out what to expect now, so you can start developing the
A task
B communication
C skill
that you need to excel in that career.
<u>Answer:</u>
Throughout your job search, you’ll find that education
is closely related to the career of your choosing. It’s important to take the time to find out what to expect now, so you can start developing the skill that you need to excel in that career.
<u>Explanation:</u>
At the time of attending our interview, we find that the question raised from an interviewer related to the choosing of the field and from our educational background. So, it clearly based on what we learn via our education and how we can get connected to the selected field but not based on our salary or an economy.
Similarly, it is essential to make a note about the requirement from the chosen field and have to prepare our skill accordingly. It means that required to develop the knowledge related to our selective field and should be presented in a connected way in front of an interviewer.
Answer:
The pH is 4.76
Explanation:
Step 1: Data given
Volume of a 0.476 M hydrocyanic acid solution = 29.8 mL = 0.0298 L
Volume of 0.487 M barium hydroxide solution = ?
Ka HCN = 6.2 * 10^-10
Step 2: Calculate pH
Hydrocyanic acid is a weak acid.
Barium hydroxide is a strong base.
The question asked = the pH BEFORE any base has been added, so we can ignore the base.
To calculate the pH of aweak acid, we need the pKa
HCN ⇔ H+ + CN-
Ka = [H+][CN-]/[HCN]
⇒ for weak acid: [H+]=[CN-]
Ka = [H+]²/[HCN]
[H+]² = [HCN]*Ka
[H+] = √([HCN]*Ka)
pH = -log(√([HCN]*Ka))
pH = -log(√(0.476 * 6.2*10^-10))
pH = 4.76
The pH is 4.76
