Physical change is the color, shape stuff like that and chemical change is once it’s changed it can’t go back
Answer:
A. 0.038 g.
Explanation:
- The decay of carbon-14 is a first order reaction.
- The rate constant of the reaction (k) in a first order reaction = ln (2)/half-life = 0.693/(5730 year) = 1.21 x 10⁻⁴ year⁻¹.
<u><em>The integration law of a first order reaction is:</em></u>
<em>kt = ln [Ao]/[A]</em>
k is the rate constant = 1.21 x 10⁻⁴ year⁻¹.
t is the time = 17,190 years.
[Ao] is the initial concentration of carbon-14 = 0.300 g.
[A] is the remaining concentration of carbon-14 = ??? g.
∵ kt = ln [Ao]/[A]
∴ (1.21 x 10⁻⁴ year⁻¹)(17,190 years) = ln (0.300 g)/[A]
2.08 = ln (0.300 g)/[A]
Taking exponential for both sides:
8.0 = (0.300 g)/[A]
<em>∴ [A] = 0.0375 g ≅ 0.038 g</em>
The number of moles contained in 39 L of F2 gas at STP is 1.74mol. Details on how to calculate number of moles can be found below.
<h3>How to calculate number of moles?</h3>
The number of moles of a gas at STP can be calculated using the following formula:
PV = nRT
Where;
- P = pressure
- V = volume
- n = number of moles
- R = gas law constant
- T = temperature
At STP, the following applies:
- T = 273K
- P = 1 atm
- R = 0.0821 Latm/molK
1 × 39 = n × 0.0821 × 273
39 = 22.41n
n = 1.74mol
Therefore, the number of moles contained in 39 L of F2 gas at STP is 1.74mol.
Learn more about number of moles at: brainly.com/question/14919968
