Answer:
0.0611M of HNO3
Explanation:
<em>The concentration of the NaOH solution must be 0.1198M</em>
<em />
The reaction of NaOH with HNO3 is:
NaOH + HNO3 → NaNO3 + H2O
<em>1 mole of NaOH reacts per mole of HNO3.</em>
That means the moles of NaOH used in the titration are equal to moles of HNO3.
<em>Moles HNO3:</em>
12.75mL = 0.01275L * (0.1198mol / L) = 0.0015274 moles NaOH = Moles HNO3.
In 25.00mL = 0.025L -The volume of the aliquot-:
0.00153 moles HNO3 / 0.025L =
<h3> 0.0611M of HNO3</h3>
Answer: The correct answer is the option: B. An element with eight valence electrons is chemically unstable.
Explanation:
Hello! Let's solve this!
We will analyze each of the options:
A. The group number of the element provides a clue to the number of valence electrons: it is correct, since it provides the number of valence electrons.
B. An element with eight valence electrons is chemically unstable: this is not correct, since elements with eight electrons in the valence shell cannot react because they already have the last complete shell. Therefore, they are chemically stable.
C. The points must be placed one at a time on each side of the chemical symbol: it is correct, because that is the way to make the point diagram.
D. An atom is chemically stable if all the points are paired: this is correct since this verifies that the point diagram has been done well.
We conclude that the correct answer is the option: B. An element with eight valence electrons is chemically unstable.
Hope this helps..... Stay safe and have a Merry Christmas!!!!!!!!! :D
3 Chlorine ions are required to bond with one aluminum ion.
In ionic bonds, metals atoms loses all its outermost shell electrons to form a cation. While, non metal atoms gains however many electrons in order to make its outermost electron shell be 8 (or 2 if there's only one shell).
Therefore, form the periodic table, we can see that aluminum has a atomic number of 13, which makes its electron arrangement be 2,8,3. So, in order to form a aluminum ion, an Al atom must lose 3 electrons. On the other hand, Chlorine has a atomic number of 17, which means it has the electron configuration of 2,8,7. It has to gain only 1 electron to have 8 outermost shell electron.
Thereofre, 3 Chlorine atom are required to gain all 3 electrons given out by just 1 aluminum ion.
Explanation:
For the first part,
Reaction equation:
N₂ + 3H₂ → 2NH₃
Given:
Number of moles of NH₃ = 6 moles
Unknown:
Number of moles of N₂ = ?
Solution:
N₂ + 3H₂ → 2NH₃;
From the reaction above, we solve from the known specie to the unknown. Ensure that the equation is balanced;
2 moles of NH₃ is produced from 1 mole of N₂
6 moles of NH₃ will be produced from 
mole of N₂
= 3moles of N₂
The number of moles of N₂ is 3 moles
ii.
Given parameters:
Number of moles of sulfur = 2.4moles
Molar mass of sulfur = 32.07g/mol
Unknown:
Mass of sulfur = ?
Solution:
The number of moles of any substance can be found using the expression below;
Number of moles = 
Mass of sulfur = number of moles of sulfur x molar mass
Insert the parameters and solve;
Mass of sulfur = 2.4 x 32.07 = 76.97g
Answer:
34.9 g/mol is the molar mass for this solute
Explanation:
Formula for boiling point elevation: ΔT = Kb . m . i
ΔT = Temperatures 's difference between pure solvent and solution → 0.899°C
Kb = Ebullioscopic constant → 0.511°C/m
m = molality (moles of solute/1kg of solvent)
i = 2 → The solute is a strong electrolyte that ionizes into 2 ions
For example: AB ⇒ A⁺ + B⁻
Let's replace → 0.899°C = 0.511 °C/m . m . 2
0.899°C / 0.511 m/°C . 2 = m → 0.879 molal
This moles corresponds to 1 kg of solvent. Let's determine the molar mass
Molar mass (g/mol) → 30.76 g / 0.879 mol = 34.9 g/mol
