Mass spectrum of Dodecane will give following information.
1 ) Molecular Peak or Parent Peak:
The Parent peak will appear at m/z = 170. The intensity of this peak will be very weak.
2) Fragments:
Usually the fragments of such long chain alkanes appear with spacing of 14 amu, Hence, the peaks in dodecane will be as follow,
170 - 156 - 142 - 128 - 114 - 100 - 86 - 72 - 58 - 44 - 30 - 16
3) Base Peak:
Most probably the Base peak will appear at m/z = 57. This peak is due to the formation of tertiary butyl cation as the intensity mainly depends upon the stability of cation. So this cation might form due to rearrangment giving the intensity of 100%.
Answer:
The student's conclusion is not correct
Explanation:
Activation energy is the minimum amount of energy required for a reaction to occur. All reactions require there activation energy to be met before the reaction can proceed. When the temperature of a reaction is increased, the kinetic energy of the reactant molecules increases; colliding more with each other, which makes them "surmount" the activation energy of the reaction faster as compared to a lower temperature.
In combustion, there is burning of an hydrocarbon (in this case propane) in excess oxygen. The burning assists in increasing the kinetic energy of the reactant particles which in turn easily surmounts the activation energy of the reaction by colliding (effective collision) more with oxygen. So, the reaction has an activation energy but the activation energy has been met and passed and hence the reaction is proceeding faster.
Increasing the temperature of a reaction is one of the ways of increasing the rate of a chemical reaction.
The sign's glass absorbed 25466.7 J
<h3>
Further explanation</h3>
Given
The temperature of glass : 23.5 °C to 65.5 °C
mass = 905 g
the specific heat capacity = 0.67 J/g °C
Required
Heat absorbed
Solution
Heat absorbed by sign's glass can be formulated :

ΔT=65.5 - 23.5 = 42

4, 2, 1, and 3 is the answer
Answer: Temperature = T, unknown
Saturated Solution, NH4Cl concentration = 60g/100g H2O = 0.6g NH4Cl/g H2O
Assume density of H2O = 1 g/ml
m = 0.6g NH4Cl/g H2O / 1 g/ml
m = 0.6g NH4Cl/ml
See the table of saturated solutions and identify the temperature at which the concentration of NH4Cl is 60g/100g H2O.
Explanation: The line on the graph on reference table G indicates a saturated solution of NH4CL as a concentration of 60. g NH4 Cl/100. g H2O