Answer: The rate constant for the reaction is 
Explanation:
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = age of sample = 559 min
a = let initial amount of the reactant = 
a - x = amount left after decay process = 



The rate constant for the reaction is 
It called cation, Well, When an atom gains or loses an electron, it
attains a net charge and becomes an ion. When electrons are lost, the
resulting ion is called cation and when electrons are gained, the
resulting ion is called an anion. So, Cations have a net positive
charge, while anions have a net negative charge. it is true.
<h2>Let us study about it .</h2>
Explanation:
Evaporation
It is the process of converting liquid into vapors .
Condensation
It is the process of converting vapors back into liquid state .
- Suppose if we have a sealed container and we are supplying it with no or little heat , we will see that as we increase heat , the particles starts moving faster .
- When they move they also colloide and transfer energies .
- The kinetic energies of certain molecule increase to an extent that they leave the other particles and escape in atmosphere .
- That is evaporation occurs .At the same time when these vapors collide with each other or with the walls of container they get cooled and again get converted to liquid state .
It is seen that a equilibrium is reached when "rate of evaporation becomes equal to rate of condensation ".
Answer : Option A)
45.5%
Explanation : We use the formula of calculating energy efficiency which is as,
η (in %)= [

] X 100
where η is energy efficiency,
and P values are for energy out and in.
So plugging the given values, we get,
η (in %) = (11825.5 / 25978.8) X 100 =
45.5 %
Answer:
83.24 mmHg.
Explanation:
- <em>The vapor pressure of the solution (Psolution) = (Xmethanol)(P°methanol).</em>
where, Psolution is the vapor pressure of the solution,
Xmethanol is the mole fraction of methanol,
P°methanol is the pure vapor pressure of methanol.
- We need to calculate the mole fraction of methanol (Xmethanol).
<em>Xmethanol = (n)methanol/(n) total.</em>
where, n methanol is the no. of moles of methanol.
n total is the total no. of moles of methanol and urea.
- We can calculate the no. of moles of both methanol and urea using the relation: n = mass/molar mass.
n of methanol = mass/molar mass = (56.9 g)/(32.04 g/mol) = 1.776 mol.
n of urea = mass/molar mass = (7.38 g )/(60.06 g/mol) = 0.123 mol.
∴ Xmethanol = (n)methanol/(n) total = (1.776 mol)/(1.776 mol + 0.123 mol) = 0.935.
<em>∴ Psolution = (Xmethanol)(P°methanol)</em> = (0.935)(89.0 mmHg) =<em> 83.24 mmHg.</em>