Answer: A) 0.20 L
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
According to the neutralization law,

where,
= molarity of stock
solution = 10.0 M
= volume of stock
solution = ?
= molarity of dilute
solution = 0.50 M
= volume of dilute
solution = 4.0 L


Therefore, the volume of 10.0 M
solution needed to prepare 4.0 L of 0.50 M
is 0.20 L
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%.
Hope this helps :) remember your conversions and just practice it's fairly easy:)
An intensive property does not change when you take away
some of the sample. The procedures that a student could use to examine the
intensive property of a rectangular block of wood are the hardness, color,
density and molecular weight.