Answer:
Explanation:
0.3(125)+0.7(126)=37.5+88.2=125.7
2. The most prevalent isotope is 32, since the average is very close to this value.
The amount of oxygen atoms present is approximately 3.27·10²³. To determine this figure, we must first assess the sodium sulfate sample. The chemical formula for it is Na₂SO₄, which possesses a molar mass of roughly 142.05 g/mol. We can then use stoichiometry to convert the mass of Na₂SO₄ into moles. By knowing the moles of Na₂SO₄, we will subsequently convert this to moles of oxygen utilizing the mole ratio and finally apply Avogadro's number to convert to atoms of oxygen. Thus, with the calculations completed, the resulting quantity of oxygen atoms is about 3.27·10²³.
Answer: 0.0007 moles of 
are released when the temperature rises.
Explanation:
To determine the moles, we utilize the ideal gas law, as follows:
where,
P = gas pressure = 1.01 bar
V = gas volume = 1L
R = gas constant = 
- Calculated moles at T = 20° C
The gas temperature = 20° C = (273 + 20)K = 293K
Substituting values into the equation gives:
- Calculated moles at T = 25° C
The gas temperature = 25° C = (273 + 25)K = 298K
Substituting values into the equation gives:
- Released moles =
Therefore, 0.0007 moles of are released when the temperature increases from 20° C to 25° C.
The molecular formula is C2H6O2
Attached is the solution:
Initially, convert the mass into moles.
Then, divide each mole by the smallest amount to identify the number of atoms in the empirical formula.
Next, calculate the empirical formula mass.
Then, determine the molecular formula by dividing the molar mass by the empirical formula mass.
Finally, multiply the empirical formula by the obtained answer to arrive at the molecular formula of the compound.
The updated volume of the balloon, when cooled at a constant pressure, is 3.98 L
Explanation
This new volume was determined using the formula from Charles' law
presented as V1/ T1 = V2/T2 where,
V1 = 4.24 L
T1= 23°C converted to kelvin = 23 + 273 = 296 K
T2 = 5.00°C converted to kelvin = 5.00 + 273 = 278 K
V2 =?
By rearranging the equation to isolate V2, we can find it by multiplying both sides by T2
V2 = V1 x T2/ T1
This results in V2 = (4.24 L x 278 K) / 296 K = 3.98 L
