Answer:
Final volume=V₂ = 216.3 mL
Explanation:
Given data:
Initial volume = 120.0 mL
Initial temperature = -12.3 °C (-12.3 +273 = 260.7 K)
Final volume = ?
Final temperature = 197.0 °C (197+273 = 470 K)
Solution:
We will apply Charles Law to solve the problem.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
V₂ = V₁T₂/T₁
V₂ = 120 mL × 470 K /260.7K
V₂ = 56400 mL.K /260.7K
V₂ = 216.3 mL
To solve this, we can use two equations.
t1/2 = ln 2 / λ = 0.693 / λ
where, t1/2 is half-life and λ is the decay constant.
t1/2 = 10 min = 0.693 / λ
Hence, λ = 0.693 / 10 min - (1)
Nt = Nο e∧(-λt)
Nt = amount of atoms at t =t time
Nο= initial amount of atoms
t = time taken
by rearranging the equation,
Nt/Nο = e∧(-λt) - (2)
From (1) and (2),
Nt/Nο = e∧(-(0.693 / 10 min) x 20 min)
Nt/Nο = 0.2500
Percentage of remaining nuclei = (nuclei at t time / initial nuclei) x 100%
= (Nt/Nο ) x 100%
= 0.2500 x 100%
= 25.00%
Hence, Percentage of remaining nuclei is 25.00%
Answer:
History of composition
Years Material Weight (grains)
1944–1946 gilding metal (95% copper, 5% zinc) 48 grains
1947–1962 bronze (95% copper, 5% tin and zinc) 48 grains
1962 – September 1982 gilding metal (95% copper, 5% zinc) 48 grains
October 1982 – present copper-plated zinc (97.5% zinc, 2.5% copper) 38.6 grains
Answer: B
Explanation: Graph B compares the two temperatures on separate lines so that we can see the comoparison directly, as a function of time. Not only does the graph quickly answer which condition id most favorable to colony growth, but it also hints at some behaviors that may accelerate growth as time goes on. Graph C is a possible answer, if the <u>only</u> question is which promotes growth the fastest. But the questions asks "compare," which Graph B does not allow as well as Graph C.
the room will either cool down or warm up the water until it is the same temperature as the room around it.
