When q is the heat energy in joules (J)
so, according to this formula, we can get q (in joule unit):
q = M*C*ΔT
when M is the mass of the water sample = 1.85 g
C is the specific heat capacity of water = 4.18 J/g.°C
and Δ T is the difference in temperature (Tf-Ti) = 33 - 22 = 11°C
So, by substitution, we will get the value of q ( in Joule):
∴ q = 1.85 g * 4.18 J/g.°C * 11 °C
= 85 J
The Molar mass of an atom corresponds directly with its atomic mass on the periodic table.
Answer:
5.8μg
Explanation:
According to the rate or decay law:
N/N₀ = exp(-λt)------------------------------- (1)
Where N = Current quantity, μg
N₀ = Original quantity, μg
λ= Decay constant day⁻¹
t = time in days
Since the half life is 4.5 days, we can calculate the λ from (1) by substituting N/N₀ = 0.5
0.5 = exp (-4.5λ)
ln 0.5 = -4.5λ
-0.6931 = -4.5λ
λ = -0.6931 /-4.5
=0.1540 day⁻¹
Substituting into (1) we have :
N/N₀ = exp(-0.154t)----------------------------- (2)
To receive 5.0 μg of the nuclide with a delivery time of 24 hours or 1 day:
N = 5.0 μg
N₀ = Unknown
t = 1 day
Substituting into (2) we have
[5/N₀] = exp (-0.154 x 1)
5/N₀ = 0.8572
N₀ = 5/0.8572
= 5.8329μg
≈ 5.8μg
The Chemist must order 5.8μg of 47-CaCO3
