The answer is 62.00 g/mol.
Solution:
Knowing that the freezing point of water is 0°C, temperature change Δt is
Δt = 0C - (-1.23°C) = 1.23°C
Since the van 't Hoff factor i is essentially 1 for non-electrolytes dissolved in water, we calculate for the number of moles x of the compound dissolved from the equation
Δt = i Kf m
1.23°C = (1) (1.86°C kg mol-1) (x / 0.105 kg)
x = 0.069435 mol
Therefore, the molar mass of the solute is
molar mass = 4.305g / 0.069435mol = 62.00 g/mol
Mass of ammonia produced : 121.38 g
<h3>Further explanation</h3>
Given
Reaction
3H₂(g) + N₂(g) ⇒ 2NH₃(g)
100g of N₂
Required
Ammonia produced
Solution
mol of N₂ :
![\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{100}{28}\\\\mol=3.57](https://tex.z-dn.net/?f=%5Ctt%20mol%3D%5Cdfrac%7Bmass%7D%7BMW%7D%5C%5C%5C%5Cmol%3D%5Cdfrac%7B100%7D%7B28%7D%5C%5C%5C%5Cmol%3D3.57)
From the equation, mol ratio of N₂ and NH₃ = 1 : 2, so mol NH₃ :
![\tt \dfrac{2}{1}\times 3.57=7.14~moles](https://tex.z-dn.net/?f=%5Ctt%20%5Cdfrac%7B2%7D%7B1%7D%5Ctimes%203.57%3D7.14~moles)
mass of NH₃(MW=17 g/mol) :
![\tt mass=mol\times MW\\\\mass=7.14\times 17\\\\mass=121.38~g](https://tex.z-dn.net/?f=%5Ctt%20mass%3Dmol%5Ctimes%20MW%5C%5C%5C%5Cmass%3D7.14%5Ctimes%2017%5C%5C%5C%5Cmass%3D121.38~g)
Answer : The concentration of
is, ![4.32\times 10^{-4}M](https://tex.z-dn.net/?f=4.32%5Ctimes%2010%5E%7B-4%7DM)
Explanation :
When we assume this reaction is driven to completion because of the large excess of one ion then we are assuming limiting reagent is
and
is excess reagent.
First we have to calculate the moles of KSCN.
![\text{Moles of }KSCN=\text{Concentration of }KSCN\times \text{Volume of solution}](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20%7DKSCN%3D%5Ctext%7BConcentration%20of%20%7DKSCN%5Ctimes%20%5Ctext%7BVolume%20of%20solution%7D)
![\text{Moles of }KSCN=0.00180M\times 0.006L=1.08\times 10^{-5}mol](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20%7DKSCN%3D0.00180M%5Ctimes%200.006L%3D1.08%5Ctimes%2010%5E%7B-5%7Dmol)
Moles of KSCN = Moles of
= Moles of
= ![1.08\times 10^{-5}mol](https://tex.z-dn.net/?f=1.08%5Ctimes%2010%5E%7B-5%7Dmol)
Now we have to calculate the concentration of ![[Fe(SCN)]^{2+}](https://tex.z-dn.net/?f=%5BFe%28SCN%29%5D%5E%7B2%2B%7D)
![\text{Concentration of }[Fe(SCN)]^{2+}=\frac{\text{Moles of }[Fe(SCN)]^{2+}}{\text{Volume of solution}}](https://tex.z-dn.net/?f=%5Ctext%7BConcentration%20of%20%7D%5BFe%28SCN%29%5D%5E%7B2%2B%7D%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20%7D%5BFe%28SCN%29%5D%5E%7B2%2B%7D%7D%7B%5Ctext%7BVolume%20of%20solution%7D%7D)
Total volume of solution = (6.00 + 5.00 + 14.00) = 25.00 mL = 0.025 L
![\text{Concentration of }[Fe(SCN)]^{2+}=\frac{1.08\times 10^{-5}mol}{0.025L}=4.32\times 10^{-4}M](https://tex.z-dn.net/?f=%5Ctext%7BConcentration%20of%20%7D%5BFe%28SCN%29%5D%5E%7B2%2B%7D%3D%5Cfrac%7B1.08%5Ctimes%2010%5E%7B-5%7Dmol%7D%7B0.025L%7D%3D4.32%5Ctimes%2010%5E%7B-4%7DM)
Thus, the concentration of
is, ![4.32\times 10^{-4}M](https://tex.z-dn.net/?f=4.32%5Ctimes%2010%5E%7B-4%7DM)
Answer:
D) One half of the carbon atoms of newly synthesized acetyl CoA.
Explanation:
It will be radioactively labeled because Malonyl CoA which contains 3 Carbon molecule is synthesized from Acetyl CoA which has 2 Carbon molecule.
This happens with the addition of ‘CO2’ with the help of the enzyme called acetyl CoA carboxylase.
<u> electrical energy to chemical energy</u>