Answer:
The mass of the element is 26.20 amu
Explanation:
In this question, we are asked to calculate the mass of an element with 15 protons, 13 electrons and 11 neutrons
To calculate the atomic mass of the element, we take into consideration the masses of the individual sub atomic particles
Electrons have 0 atomic mass unit(their masses are negligible) we have no business here, Protons have a mass of
1.00727647 amu, while the mass of neutron is 1.0086654 amu
The mass of 15 protons is thus 15 * 1.00727647 = 15.10914705 amu
The mass of 11 neutrons is 11 * 1.0086654 =
11.0953194 amu
Adding this together, we have ; 11.0953194 + 15.10914705 = approximately 26.20 amu
25
Explanation:
The coefficient 5 applis to each element in the molecule, so there are 5 times 1 H atom, 5 times 1 N atom, and ,since O has a 3 subscript, there are 5 times 3 O atoms. Therefore there are 25 atoms.
Enthalpy is energy of bonds broken - energy of bonds formed. Here, the NH3 and O2 are broken and H2O and NO are formed. So the energy to break the NH3 bonds is 3 times the amount of energy it takes to break a N-H single bond (because there are three of them in a NH3 molecule) and then multiplied by 4 because there are four particles.
So the energy of the bonds broken is 12x the energy to break a N-H single bond plus 5x the amount of energy to break an O—O double bond (you don’t multiply this by anything because in each O2 molecule there is only one bond).
The energy of the bonds formed is 6*2 = 12 Times the amount of energy for a O-H single bond plus 4 times the amount of energy required to break a N—O double bond.
Subtract energy of bonds broken - energy of bonds formed and this is the change in enthalpy.
To know what type of bond it is, draw the Lewis structure.
From the given observations,
You can see that as the concentration is doubled, half-life is halved.
That is,half-life is inversely proportional to concentration
As t( half-life) ~ 1/a^(n-1)
For this case n = 2,second order reaction.
R = k X a^n
Using the above formula you will get the rate and rate constant.
