633.97 L
Explanation:
Well use the combined gas law;
P₁V₁T₁ = P₂V₂T₂
We need to change the temperatures into Kelvin;
18.9°C= 292.05 K
5.9°C = 279.05 K
756 * 512 * 292.05 = 639 * V₂ * 279.05
113,044,377.6 = 178,312.95 V₂
V₂ = 113,044,377.6 / 178,312.95
V₂ = 633.97 L
Ch = sh = why and find the stuff
Lithium-7 is the most common isotope of lithium.
Hello!
After the addition of a small amount of acid, a reasonable value of buffer pH would be
5,15.
If initially there are equal amounts of a weak acid and its conjugate base, the pH would be equal to the pKa, according to the
Henderson-Hasselbach equation:
![pH=pKa+log( \frac{[A^{-}] }{[HA]} ) \\ \\ if [A^{-}]=[HA] \\ \\ pH=pKa + log (1) \\ \\ pH=pKa + 0=5,25](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%20%5Cfrac%7B%5BA%5E%7B-%7D%5D%20%7D%7B%5BHA%5D%7D%20%29%20%5C%5C%20%5C%5C%20if%20%5BA%5E%7B-%7D%5D%3D%5BHA%5D%20%5C%5C%20%5C%5C%20pH%3DpKa%20%2B%20log%20%281%29%20%5C%5C%20%5C%5C%20pH%3DpKa%20%2B%200%3D5%2C25)
So, when adding a little amount of acid the pH should be only a little lower than the pKa. The value from the list that is a little lower than the pKa is
5.15
Have a nice day!
Answer:
Na₂₆F₁₁
Explanation:
We find the moles of the substance assuming 100 g of the substance is present. Why do we take 100 g? Because then the percent of sodium/fluorine, would be the g of sodium/fluorine respectively:
74.186 g Sodium | 1 mol Sodium/23 g => 3.2255 mol Na
25.814 g Fluorine | 1 mol Fluorine/19 g => 1.3586 mol F
Divide each by smallest number of moles:
3.2255/1.3586 = 2.37
1.3586/1.3586 = 1
Multiply by common number to get a smallest whole number:
2.37*11 = 26,
1*11 = 11
The empirical formula is Na₂₆F₁₁