Answer:
thx for the points but I didn't understand
When the reaction equation is:
HF ↔ H+ + F-
and when the Ka expression
= concentration of products/concentration of reactions
so, Ka = [H+][F-]/[HF]
when we assume:
[H+] = [F-] = X
and [HF] = 0.35 - X
So, by substitution:
6.8 x 10^-4 = X^2 / (0.35 - X) by solving for X
∴ X = 0.015 M
∴[H+] = X = 0.015
when PH = -㏒[H+]
∴PH = -㏒0.015
= 1.8
Answer:
1) False 2) True 3) True 4) False 5) True
Explanation:
1) Platinum metal is corrosion resistant because of its less reactivity due to high ionization energy.
2) The intermediate layer of platinum group metals, are extremely dense because their crystal structures are close-packed and these atoms tend to offer numerous d electrons in a metallic bond, resulting in highly efficient packing of relatively heavy metal ions in the bulk metal.
3) The extremely high bond strengths of the PGMs result in very low thermal expansion coefficients and extremely high elastic moduli.
4) Platinum came at number 10 in metals according to its electric conductivity property. There are other metals with different valence state that have high electric conductivity than platinum.
5) PGM's occurs at the concentration of 0.005 ppm in the earth's crust, resulting in extremely high prices and the price was 32 $ per gram in 2020.
Answer:
687.5 m
Explanation:
as the given speed (or velocity) is given as 12.5 m/s and time is 55 sec...
then total distance to be travelled in 55 secs= (12.5× 55) m = 687.5 m
:)
Answer:
chloroplast is the correct answer
