Answer:
119.85 grams Br or 120. grams Br (sig figs)
Explanation:
1.50 moles Br 79.90 g Br
--------------------- x ------------------------ = 119.85 grams Br or 120 grams Br (sig figs)
1 mole
Ideal Gas law PV=nRT
P- pressure(atm)
V-volume( liter)
R- gas constant
T- temperature(kelvin)
n - number of moles
Tomato juice or acid rain
In this question we have given the gram of water and we know that 1 mole of water = 18 gram of water and 27 g of water contain 1.5 g of water 27 / 18 = 1.5 g
As we know that avogandro'S no is equal 6.022*1023
1.5g * 6.022*1023 = 9.0 * 1023 molecules present in each 27 g of water.
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For this problem we can use half-life formula and radioactive decay formula.
Half-life formula,
t1/2 = ln 2 / λ
where, t1/2 is half-life and λ is radioactive decay constant.
t1/2 = 8.04 days
Hence,
8.04 days = ln 2 / λ
λ = ln 2 / 8.04 days
Radioactive decay law,
Nt = No e∧(-λt)
where, Nt is amount of compound at t time, No is amount of compound at t = 0 time, t is time taken to decay and λ is radioactive decay constant.
Nt = ?
No = 1.53 mg
λ = ln 2 / 8.04 days = 0.693 / 8.04 days
t = 13.0 days
By substituting,
Nt = 1.53 mg e∧((-0.693/8.04 days) x 13.0 days))
Nt = 0.4989 mg = 0.0.499 mg
Hence, mass of remaining sample after 13.0 days = 0.499 mg
The answer is "e"
