<span>The first method to determine the chemical composition of a substance in space was using light. By determining red shift in the observed spectrum of light they could determine the elements they were observing. Different elements change the way light behaves and from this scientists can determine the makeup of things such as stars and nebulas.</span>
Just took it, Hydrogen bonds
Kb = [HA} [OH-] / [A-] where [A-] represents the concentration of CN- (.068M)
Kb = Kw / Ka = 1 x10-14 / 4.9 x 10-10 = 2 x 10-5
Since this is a salt solution which could be considered to have formed from the neutralization of a strong base (NaOH) and a weak acid (HCN), the Na+ will have no effect on the pH of the solution while the CN- ion will undergo hydrolysis:
CN- + H2O --> HCN + OH-
Based on this equation, the quantities of HCN and OH- produced must be the same and therefore [HCN]=[OH-]. We will set this equal to x.
Plugging into the original equation yields:
2 x 10-5 = x2 / .068 M
Solving for x yields 1.2 x 10-3 whidh is equal to the [OH-]
The pOH then is equal to -log (1.2x10-3) = 2.9
The pH of the solution would be 14 - 2.9 = 11.1
Answer:
0.42mole
Explanation:
Given parameters:
Number of atoms of titanium = 2.5 x 10²³atoms
Unknown:
Number of moles = ?
Solution:
To solve this problem, we must understand that a mole of any substance contains the Avogadro's number of particles.
6.02 x 10²³ atoms makes up 1 mole of an atom
2.5 x 10²³ atoms will contain 
= 0.42mole
Answer:
Explanation:
- The atomic number of Oxygen is 8.
- The relative atomic mass is approximately 16.
- It has 8 number of protons.
- It has 8 number of neutrons ( Atomic Mass - number of protons).
- Oxygen has 6 valence electrons.
- It has 2 energy shells, two electrons occupy the first energy shell while six electrons occupy the second energy shell.
