Answer:
151.4863 years
Explanation:
Half life, t1/2 = 100 years
Initial concentration,[A]o = 100%
Final concentration, [A] = 35% (after 65% have been decayed)
Time = ?
Half life for a first Order reaction is given as;
t1/2 = ln (2) / k
k = ln(2) / 100
k = 0.00693y-1
The integral rate law for first order reactions is given as;
ln[A] = ln[A]o − kt
kt = ln[A]o - ln[A]
t = ( ln[A]o - ln[A]) / k
t = [ln(100) - ln(35)] /0.00693
t = 1.0498 / 0.00693
t = 151.4863 years
Answer:
Option A. 1.8×10²⁴ molecules.
Explanation:
Data obtained from the question include:
Number of mole of methane = 3 moles
Number of molecules of methane =?
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ molecules.
Thus, 1 mole of methane equally contains 6.02×10²³ molecules.
With the above information in mind, we can obtain the number of molecules in 3 moles of methane as follow:
1 mole of methane contains 6.02×10²³ molecules.
Therefore, 3 moles of methane will contain = 3 × 6.02×10²³ = 1.8×10²⁴ molecules.
Thus, 3 moles of methane contains 1.8×10²⁴ molecules.
Answer:
6.1%
Explanation:
Assuming pressure inside balloon remains constant during the temperature change.
Therefore, as per Charles' law at constant pressure,
Percentage change in volume
Change in volume of the balloon is 6.1%
Answer:
The answer is
<h2>32 g</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
<h3>mass = Density × volume</h3>
From the question
volume = 40 mL
density = 0.80 g/mL
The mass is
mass = 40 × 0.8
We have the final answer as
<h3>32 g</h3>
Hope this helps you
