The rate constant, k, for the decomposition reaction : k = 0.0124 / days
<h3>Further explanation</h3>
Given
The half-life of 56 days
Required
The rate constant, k
Solution
For first-order, rate law : ln[A]=−kt+ln[A]o
The half-life : the time required to reduce to half of its initial value.
The half life :
t1/2 = (ln 2) / k
k = (ln 2) / t1/2
k = 0.693 / 56 days
k = 0.0124 / days
Answer:
(C) H3O+(aq) + C2H3O2−(aq) -> HC2H3O2(aq) + H2O(l)
Explanation:
A buffer is a solution of a weak acid and its salt. It mitigates against changes in acidity or alkalinity of a system. A buffer maintains the pH at a constant value by switching the equilibrium concentration of the conjugate acid or conjugate base respectively.
Addition if an acid shifts the equilibrium position towards the conjugate acid side while addition of a base shifts the equilibrium position towards the conjugate base side.
We are asked to convert from units of kilometer per second to units of miles per year. To do this, we need a conversion factor which would relate the different units involved. We either multiply or divide this certain value to the original measurement depending on what is asked. From literature, we will find that 1 mile is equal to 1609 meters and 1000 m is equal to 1 kilometer. Also, we will find that 3600 s is equal to 1 hr, 24 hr is equal to 1 day and 365 days is equal to 1 year. We do the conversion as follows:
3.8 km / s ( 1000 m / 1 km ) ( 1 mile / 1609 meters ) ( 3600 s / 1 hr ) ( 24 hr / 1 day ) ( 365 days / 1 year ) = 74479055.3 miles per year
Molarity is defined as number of moles of solute in 1 L of solution.
Here, 0.1025 g of Cu is reacted with 35 mL of HNO_{3} to produced Cu^{2+} ions.
The balanced reaction will be as follows:
Cu+3HNO_{3}\rightarrow Cu(NO_{3})_{2}+NO_{2}+H_{2}O
From the above reaction, 1 mole of Cu produces 1 mole of Cu^{2+}, convert the mass of Cu into number of moles as follows:
n=\frac{m}{M}
molar mass of Cu is 63.55 g/mol thus,
n=\frac{0.1025 g}{63.55 g/mol}=0.0016 mol
Now, total molarity of solution, after addition of water is 200 mL or 0.2 L can be calculated as follows:
M=\frac{n}{V}=\frac{0.0016 mol}{0.2 L}=0.008 mol/L=0.008 M
Thus, molarity of Cu^{2+} is 0.008 M.