Answer:
an acid is a substance which produces hydrogen ions as the only as the only positive ion when dissolved in water.
Closed system. If the system is not closed, matter or energy can escape from the system. an example of this is if you react magnesium and hydrochloric acid in a open system. The H₂ gas is going to escape making it look like some of the mass disappeared . in that same reaction some in an open system will also loose heat to the surrounding which will make it look like less heat was produced.
<h3>
Answer:</h3>
The root mean square speeds of O₂ and UF₆ is 513m/s and 155 m/s respectively.
<h3>
Solution and Explanation:</h3>
- To find how fast molecules or particles of gases move at a particular temperature, the root mean square speed is calculated.
- Root mean square speed of a gas is calculated by using the formula;

Where R is the molar gas constant, T is the temperature and M is the molar mass of gas in Kg.
<h3>Step 1: Root mean square speed from O₂</h3>
Molar mass of Oxygen is 32.0 g/mol or 0.032 kg/mol
Temperature = 65 degrees Celsius or 338 K
Molar gas constant = 8.3145 J/k.mol


<h3>
Step 2: Root mean square speed of UF₆ </h3>
The molar mass of UF₆ is 352 g/mol or 0.352 kg/mol


Therefore; the root mean square speeds of O₂ and UF₆ is 513m/s and 155 m/s respectively.
Answer:
pH = 5.54
Explanation:
The pH of a buffer solution is given by the <em>Henderson-Hasselbach (H-H) equation</em>:
- pH = pKa + log
![\frac{[CH_3COO^-]}{[CH_3COOH]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BCH_3COO%5E-%5D%7D%7B%5BCH_3COOH%5D%7D)
For acetic acid, pKa = 4.75.
We <u>calculate the original number of moles for acetic acid and acetate</u>, using the <em>given concentrations and volume</em>:
- CH₃COO⁻ ⇒ 0.377 M * 0.250 L = 0.0942 mol CH₃COO⁻
- CH₃COOH ⇒ 0.345 M * 0.250 L = 0.0862 mol CH₃COOH
The number of CH₃COO⁻ moles will increase with the added moles of KOH while the number of CH₃COOH moles will decrease by the same amount.
Now we use the H-H equation to <u>calculate the new pH</u>, by using the <em>new concentrations</em>:
- pH = 4.75 + log
= 5.54