Answer:
Explanation:
To determine the age, we need to know how much U have become Pb, so first we have to calculate the Pb moles present in a sample:
The percentage of U degradation:
Assuming that the life time is linear:
2. How much heat is released when 432g of water cools down from 710C to 180C?
1 answer:
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Answer:
Molecules in order of decreasing rate of effusion:
Explanation:
Mass of gas=
Mass of gas =
Mass of gas =
Mass of gas =
According Graham's law:
'The rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas'.The equation given by this law follows the equation:
So, higher the molecular mass of the gas lower will be the effusion rate and vice versa.
Increasing order of molecular masses of the given gases:
Decreasing order of effusion rate respective to gases:
Molecules in order of decreasing rate of effusion:
Answer:
A. 4500 mL
Explanation:
We need to use a version of the combined gas law, which states:
, where T represents temperature, V volume, and n moles
First, look at the initial values of n, V, and T:
- n: we have 10.0 grams of hydrogen, which we need to convert to moles. So:
- V: we have a volume of 5.0 L
- T: our temperature right now is 28.0°C, but we need it in Kelvins, so add 273: 28.0 + 273 = 301 K
Now look at the final values:
- n: our final number of grams is 8.5 grams of hydrogen, so we need to convert this to moles.
- V: this is what we want to find
- T: our final temperature is 44.0°C; to convert it to Kelvins, add 273.
44.0 + 273 = 317 K
Put this altogether:
Multiply both sides by (4.2 * 317):
≈ 4.5 L
However, the problem wants millilitres, so simply multiply 4.5 by 1000:
4.5 * 1000 = 4500
The answer is thus A.