Atomic mass Si = 28.0855 u.m.a
28.0855 g -------------------- 6.02x10²³ atoms
3.96x10³ g ------------------- ?? atoms
( 3.96x10³) x 6.02x10²³ / 28.0855 =
8.48x10²⁵ atoms
Answer:
The hydroxide [OH-] concentration of the solution is 1.26*10⁻⁵ M.
Explanation:
The pOH (or potential OH) is a measure of the basicity or alkalinity of a solution.
POH indicates the concentration of hydroxyl ions [OH-] present in a solution and is defined as the negative logarithm of the activity of hydroxide ions (that is, the concentration of OH- ions):
pOH= -log [OH-]
A solution has a pOH of 4.90. Replacing in the definition of pOH:
4.90= -log [OH-]
Solving:
-4.90= log [OH-]
1.26*10⁻⁵ M= [OH-]
<u><em>The hydroxide [OH-] concentration of the solution is 1.26*10⁻⁵ M.</em></u>
Answer:
the pressure exerted in pascals is 0.5 Pa
Explanation:
The computation of the pressure exerted in pascals is shown below:
As we know that
Pressure = force ÷ area
= 25 ÷ 50
= 0.5 Pa
Hence, the pressure exerted in pascals is 0.5 Pa
We simply applied the above formula so that the correct pressure could come
Answer is: <span>the charge of the iron in this compound is +2.
Atomic mass of iron is 55,8 g/mol.
Atomic mass of chlorine is 35,5 g/mol.
If compound is FeCl, molar mass would be 55,8 </span>g/mol + 35,5 g/mol = 91,3 g/mo, that is not correct.
If compound is FeCl₂, malar mass of compound would be:
55,8 g/mol + 2·35,5 g/mol = 126,8 g/mol, that is correct.
Oxaidation number of chlorine is -1.
