Answer:
pH of the final solution = 9.15
Explanation:
Equation of the reaction: HCl + NH₃ ----> NH₄Cl
Number of moles of NH₃ = molarity * volume (L)
= 0.4 M * (300/1000) * 1 L = 0.12 moles
Number of moles of HCl = molarity * volume (L)
= 0.3 M * (175/1000) * 1 L = 0.0525 moles
Since all he acid is used up in the reaction, number of moles of acid used up equals number of moles of NH₄Cl produced
Number moles of NH₄Cl produced = 0.0525 moles
Number of moles of base left unreacted = 0.12 - 0.0525 = 0.0675
pOH = pKb + log([salt]/[base])
pKb = -logKb
pOH = -log (1.8 * 10⁻⁵) + log (0.0525/0.06755)
pOh = 4.744 + 0.109
pOH = 4.853
pH = 14 - pOH
pH = 14 - 4.853
pH = 9.15
Therefore, pH of the final solution = 9.15
Answer:
Scandium is the smallest element of the four
Explanation:
Vanadium = 50.9415 u
Titanium = 47.867 u
Scandium = 44.955912 u
Chromium = 51.9961 u
Answer:
by the VSEPR theory.
Explanation:
This question is asking for the bond angle of the 
bond in 
. The VSEPR (valence shell electron pair repulsion) theory could help. Start by considering: how many electron domains are there on the carbon atom between these two bond?
Note that "electron domains" refer to covalent bonds and lone pairs collectively.
- Each nonbonding pair (lone pair) of valence electrons counts as one electron domain.
- Each covalent bond (single bond, double bond, or triple bond) counts as exactly one electron domain.
For example, in , the carbon atom at the center of that bond has two electron domains:
- This carbon atom has two double bonds: one
bond and one 
bond. Even though these are both double bonds, in VSEPR theory, each of them count only as one electron domain. - Keep in mind that there are only four valence electrons in each carbon atom. It can be shown that all four valence electrons of this carbon atom are involved in bonding (two in each of the two double bonds.) Hence, there would be no nonbonding pair around this atom.
In VSEPR theory, electron domains around an atom repel each other. As a result, they would spread out (in three dimensions) as far away from each other as possible. When there are only two electron domains around an atom, the two electron domains would form a straight line- with one domain on each side of the central atom. (To visualize, consider the three atoms in this bond as three spheres on a stick. The central 
atom would be between the other atom and the 
atom.)
This linear geometry corresponds to a bond angle of .
<span>It is known that amu is equal to the molar mass of 1 mole of substance. Therefore,
</span>
Weight of one mole of uranium = 238 g/mol
The molar mass or molecular weight for U205 is 556 g/mol.
(238 x 2) + (16 x 5) = 556 g/mol
