Answer:
The answer to your question is below
Explanation:
a)
Number of atoms = ?
moles of Fe = 4.75
-Use proportions to solve this problem
1 mol of Fe --------------------- 6.023 x 10²³ atoms
4.75 moles --------------------- x
x = (4.75 x 6.023 x 10²³) / 1
x = 2.86 x 10²⁴ / 1
Number of atoms = 2.86 x 10²⁴
b)
Number of moles = ?
moles of 1.058 moles of H₂O
I think this question is incorrect, maybe you wish to know the number of atoms or grams of H₂O.
c)
Number of atoms = ?
moles of Fe = 0.759
1 mol of Fe ------------------ 6.023 x 10²³ atoms
0.759 moles --------------- x
x = (0.759 x 6.023 x 10²³) / 1
x = 4.57 x 10²³ / 1
Number of atoms of Fe = 4.57 x 10²³ atoms
d)
Number of molecules = ?
moles of H₂O = 3.5 moles
1 mol of H₂O ------------------ 6.023 x 10²³ molecules
3.5 moles ------------------ x
x = (3.5 x 6.023 x 10²³) / 1
x = 2.11 x 10²⁴ molecules
Number of molecules = 2.11 x 10²⁴
d = √((x1 - x2)2 + (y1 - y2)2)
( -2 , 5 ) ( 12 , -1 )
↑ ↑ ↑ ↑
x1 y1 x2 y2
d = √((-2 - 12)2 + (5 - (-1))2) = √((-14)2 + 62) = √(196 + 36) = √232 = 2√58 ≈ 15.23
Answer: A supersaturated solution will not contain undissolved solute because the undissolved solute will be indicative of saturated solution.
Explanation:
A supersaturated solution is the one that consists of more than the maximum concentration of the solute in the solvent that is being dissolved at a given temperature. A saturated solution is the one in which the maximum concentration of solute has been dissolved in the solvent and no additional solute can be dissolved further.
According to the given statement, a solution with undissolved solute is a saturated solution rather a supersaturated solution.
<u>Answer:</u> The concentration of radon after the given time is 
<u>Explanation:</u>
All the radioactive reactions follows first order kinetics.
The equation used to calculate half life for first order kinetics:
We are given:
Putting values in above equation, we get:
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = 3.00 days
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial amount of the reactant = 
[A] = amount left after decay process = ?
Putting values in above equation, we get:
![0.181days^{-1}=\frac{2.303}{3.00days}\log\frac{1.45\times 10^{-6}}{[A]}](https://tex.z-dn.net/?f=0.181days%5E%7B-1%7D%3D%5Cfrac%7B2.303%7D%7B3.00days%7D%5Clog%5Cfrac%7B1.45%5Ctimes%2010%5E%7B-6%7D%7D%7B%5BA%5D%7D)
![[A]=3.83\times 10^{-30}mol/L](https://tex.z-dn.net/?f=%5BA%5D%3D3.83%5Ctimes%2010%5E%7B-30%7Dmol%2FL)
Hence, the concentration of radon after the given time is
Answer:
pH = 4.58
Explanation:
The reaction of NaOH with acetic acid, CH₃COOH occurs as follows:
NaOH + CH₃COOH → CH₃COO⁻Na⁺ + H₂O
<em>Moles that react:</em>
NaOH = 10mL = 0.010L * (0,240mol / L) = 0.0024 moles NaOH
CH₃COOH = 50.0mL = 0.050L * (0.120mol / L) = 0.0060 moles CH₃COOH
That means after the reaction you will have:
CH₃COOH: 0.0060 mol - 0.0024 mol = 0.0036 moles
CH₃COO⁻Na⁺: 0.0024 moles
in solution, you will have the mixture of a weak acid (Acetic acid), with its conjugate base (sodium acetate, CH₃COO⁻Na⁺). And pH of this buffer can be determined using H-H equation:
pH = pKa + log [A⁻] / [HA]
For Acetic buffer pKa = 4.76:
pH = 4.76 + log [CH₃COO⁻Na⁺] / [CH₃COOH]
<em>Where [] is molarity of each species or moles</em>
<em />
Replacing:
pH = 4.76 + log [0.0024 moles] / [0.0036 moles]
<h3>pH = 4.58</h3>
<em />
