Answer:
20.5 × 10²³ molecules of He
Explanation:
Given data:
Number of moles of He = 3.40 mol
Number of molecules of He = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For 3.40 moles of He:
3.40 mol × 6.022 × 10²³ molecules
20.5 × 10²³ molecules of He
Assuming that the initial pH is pHi.
The initial concentration of [OH-] is
[OH]- = 10^(14 - pHi)
Since half of the Na2HPO4 is neutralized, the concentration of [OH-] will be reduced to half. The new pH will be
[OH-]/2 = 10^(14 - pHi)/2 = 10^(14 - pH)
14 - pHi - log 2 = 14 - pH
In terms of pHi,
pH = pHi + log 2
The two errors in the data resulting from an experiment where the temperature is raised too quickly are: First, the melting point temperature may not be recorded correctly since it cannot be monitored closely if the heat supplied is too high. <span />
I believe the bond between between F and Cl would be polar covalent.
