Hi. You did not provide any response options. However, a PCR reaction proceeds as follows.
After the primers are added to the test tube containing the PCR components. This tube is placed in a device called a thermocycler. At that moment, the stage called denaturation will begin, where the thermocycler increases the temperature to the point of breaking the hydrogen bonds that hold the two strands of DNA together. The thermal cycler increases the temperature up to 96°C.
After that, the second step of the reaction begins. At that moment, the thermal cycler lowers the temperature to 55º - 65ºC, which is the ideal temperature for the primers to be able to attach themselves to the DNA strands, preparing them for the presence of the polymerase.
After that, the thermocycler raises the temperature to 72ºC, which is the ideal temperature for the DNA polymerase to work. At this stage, the DNA polymerase will use the DNA strand and the primer to build a new DNA strand, which will be annealed to the DNA strand used as a template.
These three steps will be repeated about 35 times, generating many copies of DNA.
Explanation:
The integrated rate law for the zeroth order reaction is:
![[A]=-kt+[A]_0](https://tex.z-dn.net/?f=%5BA%5D%3D-kt%2B%5BA%5D_0)
The integrated rate law for the first order reaction is:
![[A]=[A]_0e^{-kt}](https://tex.z-dn.net/?f=%5BA%5D%3D%5BA%5D_0e%5E%7B-kt%7D)
The integrated rate law for the second order reaction is:
![\frac{1}{[A]}=kt+\frac{1}{[A]_0}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B%5BA%5D%7D%3Dkt%2B%5Cfrac%7B1%7D%7B%5BA%5D_0%7D)
Where,
![[A]](https://tex.z-dn.net/?f=%5BA%5D)
is the active concentration of A at time t
![[A]_0](https://tex.z-dn.net/?f=%5BA%5D_0)
is the active initial concentration of A
t is the time
k is the rate constant
Answer:
Kr
Explanation:
Now we have to apply Graham's law of diffusion in gases
t1/t2 = √M1/M2
If t1 is the time of diffusion of Xe = 75 seconds
t2 is the time of diffusion of the unknown gas = 60 seconds
M1= molar mass of Xe=131.293
M2= molar mass of the unknown gas
Thus;
75/60 = √131.293/M2
(75/60)^2= (√131.293/M2)^2
5625/3600=131.293/M2
M2= 3600×131.293/5625
M2= 84.0
The unknown gas is krypton (Kr)
Answer:
Enthalpy of formation to the nearest KJ = -275KJ
Explanation:
Enthalpy of formation is the heat change when one mole of a substance is formed from its element in its standard states and in standard conditions of temperature and pressure. it may be positive or negative, if positive, it is an endothermic reaction where the heat content of the product is greater than that of the reactants. and if negative, it is exothermic reaction - where the heat content of the reactants is greater than the products. the enthalpy of formation is measured in Kilo-Joule/Moles (KJ/Mole).
A detailed step by step calculation of the enthalpy of formation of one mole lead (II) sulfate of is attached below.
