Among all three PCl₃, NO₃⁻ , I₃⁻, H₂Se only I₃⁻ will involve participation of d-orbitals in hybridization as bonding in I₃⁻ will include, s, p and d orbital as shown in the image attached. there will be sp³d hybridization, there will be presence of three lone pairs and 2 bonds as
I⁻ has 8 valence electrons and 2 neighbours atoms which will need one electron each to satisfy their valency.
so the number of electrons on central atom will be:
8-1-1=6
That 6 electrons will make 6/2 =3 lone pairs.
Answer:
4.88 Cals per degree celsius
Explanation:
We have taken heat of fusion of ice = 80 cals / g
We have taken speciic heat of water = 1 cal/g per degree celsius
In this experiment , let the heat capacity of calorimeter be X.
Heat gained by ice
heat gained in melting + heat gained in getting warmed
= mass x latent heat + mass x specific heat x rise in temperature
= 17.69 x 80 + 17.69 x 1 x ( 12.9 - 0 )
= 1643.4 Cals
Heat lost by water
= mass x specific heat x fall in temperature
98.67 x 1 x ( 28.77 - 12.9 )
= 1565.89 Cals
Heat lost by calorimeter
heat capacity x fall in temperature
X x ( 28.77 - 12.9 )
Heat gained = heat lost
1643.4 = 1565.89 +15.87X
X = 4.88 Cals per degree celsius
b. 3.35
c. 2.41
d. 1.48
e. 7.00
Answer:
b. 3.35
Explanation:
To calculate the pH of a solution containing both acid and its salt (produced as a result of titration) we need to use Henderson’s equation i.e.
pH = pKa + log ([salt]/[acid]) (Eq. 01)
Where
pKa = -log(Ka) (Eq. 02)
[salt] = Molar concentration of salt produced as a result of titration
[acid] = Molar concentration of acid left in the solution after titration
Let’s now calculate the molar concentration of HNO2 and KOH considering following chemical reaction:
HNO2 + KOH ⇆ H2O + KNO2 (Eq. 03)
This shows that 01 mole of HNO2 and 01 mole of KOH are required to produce 01 mole of KNO2 (salt). And if any one of them (HNO2 and KOH) is present in lower amount then that will be considered the limiting reactant and amount of salt produced will be in accordance to that reactant.
Moles of HNO2 in 50 mL of 0.01 M HNO2 solution = 50/1000x0.01 = 0.005 Moles
Moles of KOH in 25 mL of 0.01 M KOH solution = 25/1000x0.01 = 0.0025 Moles
As it can be seen that we have 0.0025 Moles of KOH therefore considering Eq. 03 we can see that 0.0025 Moles of KOH will react with only 0.0025 Moles of HNO2 and will produce 0.0025 Moles of KNO2.
Therefore
Amount of salt produced i.e [salt] = 0.0025 moles (Eq. 04)
Amount of acid left in the solution [acid] = 0.005 - 0.0025 = 0.0025 moles (Eq.05)
Putting the values in (Eq. 01) from (Eq.02), (Eq. 04) and (Eq. 05) we will get the following expression:
pH= -log(4.5x10 -4) + log (0.0025/0.0025)
Solving above we get
pH = 3.35
The pH value in the titration flask after 25.00 mL of the 0.10 M KOH solution is added to 50.00 mL of 0.10 M HNO2 solution is 3.35.
The subject of this question is titration, which is a method used in chemistry to measure the concentration of an unknown solution. Given 50.00 mL of 0.10 M HNO2 (nitrous acid, Ka = 4.5 × 10-4), titrated with 0.10 M KOH (potassium hydroxide), we need to calculate the pH after 25.00 mL of the KOH solution is added.
First, we need to find the moles of the HNO2 and the KOH. Moles equals Molarity times Volume. So, for HNO2, it is 0.10 M * 0.050 L which equals 0.005 moles. For KOH, it is 0.10 M * 0.025 L which equals 0.0025 moles.
Then, subtract the moles of OH- from the moles of HNO2 to determine the concentration of HNO2 left, which is 0.005 moles - 0.0025 moles = 0.0025 moles. Divide this by the total volume of the solution (50.00 mL + 25.00 mL = 75.00 mL or 0.075 L to determine the new concentration of HNO2, 0.0025 moles / 0.075 L = 0.033 M. Then use the given Ka value with the equation [H+] = sqrt(Ka * [HNO2]) to get [H+].
To find acids' pH, we use the formula pH = -log[H+]. Use the calculated [H+] to find the pH.
Upon performing these calculations, the resulting pH value should be approximately 3.35 after 25.00 mL of the KOH solution is added, so the answer is (b) 3.35.
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Answer:
1) 108.27 grams of potassium nitarte must be added to 275 mL of water to produce a solution that freezes at -14.5°C.
2) 1.73 is the actual value of the van't Hoff factor, i.
Explanation:
1) Formula used depression in freezing point ;
where,
=Freezing point of solution
T = Freezing point of water
=depression in freezing point =
i = van't Hoff factor of solute
= freezing point constant
m = molality of solution
We have :
of water = 1.86°C/m ,
Molality of solution = m = ?
i = 2
Freezing point of solution =
Freezing point of pure water = T = 0°C
m = 3.898 molal
3.898 moles of potassium nitrate is dissolved in 1 kg of water or 1000 g of water.
Volume of water , V= 275 ml
Mass of water = m
Density of water= d = 1 g/mL
Here, 3.898 moles of potassium nitrate is dissolved in 1 kg of water or 1000 g of water. Then moles of potassium nitarte present in 275 grams of water is :
Mass of 1.072 moles of potassium nitrate :
1.072 mol × 101 g/mol = 108.27 g
108.27 grams of potassium nitarte must be added to 275 mL of water to produce a solution that freezes at -14.5°C.
2) Formula used an Elevation in boiling point;
where,
=boiling point of solution
T = boiling point of water
=Elevation in boiling point =
i = van't Hoff factor of solute
= Boiling point constant
m = molality of solution
of the solution
We have :
of water = 0.512°C/m ,
Molality of solution = m = 3.90 m
i =?
The boiling point of pure water = T = 100.00°C
The boiling point of solution = = 103.45°C
1.73 is the actual value of the van't Hoff factor, i.
B. How many grams of copper are in the necklace.?
C. If the 18- karat gold has a density of 15.5g/cm^3, what is the volume in cubic centimeters?
Fullyexlplain your answer.
Answer: No I+ cannot be called a Lewis base.
Explanation:
According to Lewis Theory, it defines an acid as an electron-pair acceptor and a base as an electron-pair donor.
In terms of Lewis basicity, Iodide ion (anions) has the more readily available lone pair electrons for donation since iodide ion is less electronegative .
With the help of the net electronic structure one can understand the answer of the question, because we need to study the I+ ion (cation) structure.
Lewis acid is therefore any substance, that can accept a pair of nonbonding electrons.
From the picture below I+ is most likely ready to accept electrons not to give from it 5s orbital to become stable.
The quantity of acetic acid that is needed to prepare the 500 mL buffer is 9.0075 grams.
Given the following data:
First of all, we would write the equilibrium chemical reaction for acetate-acetic acid as follows:
Next, we would calculate HA by applying Henderson-Hasselbalch equation:
Where:
Substituting the given parameters into the formula, we have;
For the concentration of both acids, we have:
For acetate ion:
At a volume of 0.5 liters, we have:
By stoichiometry:
Total moles = = 0.15 moles.
Mass = 9.0075 grams.
Read more on moles here: brainly.com/question/3173452
Answer:
You will need 9,0 g of acetic acid
Explanation:
The equilibrium acetate-acetic acid is:
CH₃COOH ⇄ CH₃COO⁻ + H⁺ pka = 4,76
Using Henderson-Hasselbalch you will obtain:
pH = pka + log₁₀
Where HA is acetic acid and A⁻ is acetate ion
4,90 = 4,76 + log₁₀
1,38 = (1)
As acetate concentration is 0,300M:
0,300M = [HA] + [A⁻] (2)
Replacing (2) in (1):
[HA] = 0,126 M
And:
[A⁻] = 0,174 M
As you need to produce 500 mL:
0,5 L × 0,126 M = 0,063 moles of acetic acid
0,5 L × 0,174 M = 0,087 moles of acetate
To produce moles of acetate from acetic acid:
CH₃COOH + NaOH → CH₃COO⁻ + Na⁺ + H₂O
Thus, moles of acetate are equivalents to moles of NaOH and all acetates comes from acetic acid, thus:
0,087 moles of acetate + 0,063 moles of acetic acid ≡ 0,15 moles of acetic acid × = 9,0 g of acetic acid
I hope it helps!