The number of particles (molecules, atoms, compounds, etc.) per mole of a substances is known as Avagadro number. It is equal to 6.022×10^23 mol-1 and is expressed as NA.
Number of moles is the amount of a substance that contains as many particles as there are atoms in 12 grams of pure carbon-12. So, 1 mol contains 6.022×10^23 elementary entities of the substance. Since 6.022 x 10^23 is the Avagadro number, one mole is equal to Avagadro number.
One mole of a substance is the ratio of mass of the substance by the molecular mass of the substance. Thus the mass of one mole of a substance is equal to the substance's molecular weight. Thus one mole of a substance is the atomic mass unit of a substance and since one mole is equivalent to the Avagadro number,we can conclude that one Avagadro number is one atomic mass unit of the substance.
Answer:
1) Big Bang Theory
2) we are in a phase of the big bang theory
Explanation:
So for number 1 the answer is the -big bang theory- and number 2 there is a theory that pretty much says that were in a constant cycle. what I mean is theoretically in a couple million years the entire universe will form together again into another dense ball and repeat the process. So basically the universe is still in the "expanding phase" and that's what backs up the theory of the big bang (the fact that were in one of the big bang theory's "phases")
Answer:
The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34 respectively.
Explanation:
pH - short for hydrogen potential - is a measure of the acidity or alkalinity of a solution. So the pH is a parameter that indicates the concentration of hydrogen ions [H]⁺ that exist in a solution.
The pH is expressed as the negative base 10 logarithm of the hydrogen ion concentration. This is represented by:
pH= - log [H⁺]
pH is measured on a scale of 0 to 14. On this scale, a pH value of 7 is neutral, which means that the substance or solution is neither acidic nor alkaline. A pH value of less than 7 means that it is more acidic, and a pH value of more than 7 means that it is more alkaline.
HBr is a strong acid. Then, in aqueous solution it will be totally dissociated. So the proton concentration is equal to the initial concentration of acid:
[H⁺]= [HBr]= 2.2*10⁻³ M
So:
pH= - log (2.2*10⁻³)
pH= 2.66
On the other hand, pOH is a measure of the concentration of hydroxyl ions in a solution. The sum of pH and pOH equals 14:
pH + pOH= 14
2.66 + pOH= 14
pOH= 14 - 2.66
pOH= 11.34
<u><em>The pH and pOH of a 2.2*10⁻³ HBr solution is 2.66 and 11.34 respectively.</em></u>
