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Answer:
3.00x10²⁵ atoms of chromiun
Explanation:
The formula of aluminum dichromate is Al₂(Cr₂O₇)₃.
In the formula it is seen that for each molecule of the compound, we have 6 chromium atoms, so in one mole of it, there are 6 moles of chromium. With this information you can calculate the amount of chromium atoms using Avogadro's number.
Since we know that in one mole there are 6.02x10²³ molecules of aluminum dichromate, and <em>in each molecule there are 6 chromium atoms</em>, so the following relationship can be established:
1 mole Al₂(Cr₂O₇)₃ _____ 6 x (6.02x10²³) Chrome atoms
8.3 moles _____ X = 3.00x10²⁵ atoms
Calculation:
8.3 moles x [6 x (6.02x10²³)] / 1 mol = 2.9979x10²⁵ atoms ≅ 3.00x10²⁵atoms
The answer, then, is that <em>there are 3.00x10²⁵ chromium atoms in 8.3 moles of aluminum dichromate</em>
Answer:
Explanation:
The ionization constant of the water = at a temperature of and pressure of 20 MPa
Water dissociates as;
The expression for the ionization constant is :
For pure water,
So,
The concentration of the hydroxide ions, .
Answer:
The answer to your question is 0.82 moles of CO₂
Explanation:
Data
V = 10L
T = 25°C
P = 1 atm
moles = n = ?
R = 0.08205 atm L/mol°K
Process
1.- Convert °C to °K
T = 25 + 273 = 298°K
2.- Use the ideal gas law to find the moles of Acetylene
PV = nRT
Solve for n
n = PV / RT
Substitution
n = (1)(10) / (0.08205)(298)
Simplification
n = 10 / 24.45
Result
n = 0.409 moles of Acetylene
3.- Use proportions to find the moles of CO₂
2 moles of C₂H₂ ------------------- 4 moles of CO₂
0.409 moles ------------------- x
x = (0.409 x 4) / 2
x = 1.636 / 2
x = 0.82 moles of CO₂
Starting pH = pKa because the acid and conjugate base have equal concentrations.
pH = pKa = -log(1.8*10–5) = 4.74
0.0100 L • 1.00 M = 0.0100 mol HCl, which reacts with the conjugate base, producing 0.0100 mol of weak acid.
You now have 0.110 mol weak acid and 0.090 mol conjugate base. Use the Henderson-Hasselbach equation to solve for pH now.
pH = 4.74 + log(0.090/0.110) = 4.65
The equation technically says to use concentrations of the acid and base, but that doesn’t actually matter, because it would give the same answer.