<span>The half-life of a first-order reaction is determined as follows:
</span>t½<span>=ln2/k
From the equation, we can calculate the </span><span>first-order rate constant:
</span>k = (ln(2)) / t½ = 0.693 / 90 = 7.7 × 10⁻³
When we know the value of k we can then calculate concentration with the equation:
A₀ = 2 g/100 mL
t = 2.5 h = 150min
A = A₀ × e^(-kt) =2 × e^(-7.7 × 10⁻³ × 150) = 0.63 g / 100ml
= 6.3 × 10⁻⁴ mg / 100ml
Try 22.4 and see if that works
Answer:
260 moles of Helium
Explanation:
V = 50L
T = 20°C = (20 + 273.15)K = 293.15K
P = 125 atm
R = 0.082 L.atm / mol. K
n = ?
From ideal gas equation,
PV = nRT
P = pressure of a given gas
V = volume it occupies
n = number of moles
R = ideal gas constant
T = temperature of the gas
PV = nRT
n = PV / RT
n = (125 * 50) / (0.082 * 293.15)
n = 6250 / 24.0383
n = 260.00 moles
The child inhaled 260 moles of Helium
Answer: 1.41725 X 10^{24} atoms
Explanation:
One male of any gas containing no. of atoms
2.5 moles of gas containing no. of atoms
The given gas is triatomic gas. Hence
No. of atoms
