The concentration of OH- ( symbol: [OH-] ), is equal to 10^-pOH (ten to the pOH'th power). The pOH equals 14 minus the pH, because the pH + the pOH = 14. So the pOH is 14-13= 1. Now the concentration of OH- is 10^-1 (= 1) moles/Litre
<span>NaOH (s) --> Na+ (aq) + OH- (aq) </span>
<span>1. : 1. : 1 </span>
<span>So by dissolving one mole of NaOH, you get one mole of Na+ and one mole of OH-. Meaning that the molarity (number of solved NaOH in one Litre) of NaOH is 1 mole/Litre, because the ratio is 1:1. This means, in ten litres of water there are also ten moles of NaOH. And the weight of one mole of NaOH is 40.00 grams (look it up in literature). So in ten litres solution with a pH of 13, there are 40.00*10 = 400 = 4 * 10^2 grams of NaOH dissolved</span>
Density is calculated using the following rule:
density = mass / volume
therefore:
mass = density * volume
mass of Hg = 13.6 * 60.2 = 818.72 grams
From the periodic table:
molar mass of Hg = 200.59 grams
number of moles = mass / molar mass
number of moles of Hg = 818.72 / 200.59 = 4.08 moles
each mole contains Avogadro's number of atoms.
Therefore,
number of atoms in the given sample = 4.08 * 6.022 * 10^23
= 2.456976 * 10^24 atoms
Answer:
to change an atom labeled + ion or -ion into a neutral atom, an electron is either added or removed from it
As a couple of people have pointed out, human hearing ranges from 10 Hz to 10,000 Hz, but as people get older and as they damage their hearing by listening to very loud music, firing guns without ear protection, working in very noisy environments or having other physical damage, that upper end drops off. At 64 yrs old, with a long history of a target shooter before we thought about ear protection, and after many years as a rock and roll disk jockey.<span>
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Answer:
2.173 moles of ethanol is presented in a 100.0g sample of ethanol .
Explanation:
The amount of substance that contains as many Particles as there are atoms in exactly 12g of carbon- '12 isotope is called 1 mole '= 46 u.
