Answer:
The atomic mass of lead is: 207.216 u
Explanation:
data Isotopes mass percent
1 203.97302 1.4
2 205.974444 24.1
3 206.97587 22.1
4 207.97663 52.4
atomic mass = (203.97302x 0.014) + (205.974444 x 0.241) +
(206.97587 x 0.221) + (207.97663 x 0.524)
atomic mass = 2.856 +49.639 + 45.742 + 108.979
atomic mass = 207.216 u
Answer:
- The first equation, <em>a. PV = nRT</em>, <u>is not</u> <em>a valid statement of the ideal gas law.</em>
Explanation:
The basic expression for the<em> ideal gas law</em> is:
- .......... [Equation 1]
Where:
- n is the number of moles of the gas
- V is the volume occupied by the gas
- p is the pressure exerted by the gas molecules
- T is the temperature in absolute scale (Kelvin)
- R is the Universal gas constant (0.0821 atm-liter /K-mol or the equivalents in other units)
You can perform different algebraic operations to obtain equivalent equations:
<u>Choice b) Divide equation 1 by T and you get</u>:
- pV / T = nR, which is the choice b. from your list.
<u>Choice c) Divide equation 1 by n × V and you get</u>:
- p/n = RT / V, which is the choice c. from your list.
<u>Choice d) Divide equation 1 n × T and you get</u>:
- pV / (nT) = R, which is the choice d. from your list.
The choice a. p = nRTV states that p and V are in direct relation, when the ideal gas law states that p and V are inversely related, so that equation is wrong.
<u>Conclusion: </u>the choice a, p = nRTV, is not a statement of the ideal gas law.
Answer:
[CO] = 7.61x10⁻³M
7.61x10⁻³x10³ = 7.61
Explanation:
For a generic equation aA + bB ⇄ cC + dD, the constant of equilibrium (Kc) is:
We need to know the molar concentrations in the equilibrium. In the beginning, there is only COCl₂, and its concentration is the number of moles divided by the volume:
[COCl₂] = 7.73/10.0 = 0.773 M
So, the equilibrium will be:
COCl₂(g) ⇆ CO(g) + Cl₂(g)
0.773 0 0 <em>Initial</em>
-x +x +x <em> Reacts</em>
0.773-x x x <em>Equilibrium</em>
Supposing that x<<0.773, then:
7.5x10⁻⁵ = x²/0.773
x² = 5.7975x10⁻⁵
x = √5.7975x10⁻⁵
x = 7.61x10⁻³ M
The supposing is correct, so [CO] = 7.61x10⁻³ x 10³ = 7.61
Answer:
A. by measuring the CO2 concentration in trapped gases in the ice layers
Explanation:
By looking at past concentrations of greenhouse gasses in layers in ice cores, scientists can calculate how modern amounts of carbon dioxide and methane compare to those of the past, and, then, compare past concentrations of greenhouse gasses to temperature.