I'm assuming that C is carbon.

55.1259 g of C
The simple formula is C = n/V
n = mols
C = Concentration or Molarity
V = Volume in Liters.
n = 2
V = 4
C = 2 / 4
C = 0.5 mol/Litre
The element that will have the lowest electronegativity is an element with a small number of valence electrons and a large atomic radius.
Electronegativity of an element is the ability or power of that element in a molecule to attract electrons to its Valence electrons. The following are the properties of electronegativity:
- It increases across a period from left to right of the periodic table,
- It decreases down the periodic table groups
- Group 1 elements are the least (lowest) electronegative elements. These elements have the lowest valence electrons with a large atomic radius.
- Group 7 elements are the most electronegative elements.
Atomic radius of elements increase down a group because of a progressive increase in the number of shells occupied by electrons which increases the size. But it decreases across a period because electrons are accommodated within the same shell leading to greater attraction by the protons in the nucleus.
Learn more about electronegativity of elements here:
brainly.com/question/20348681
Answer: a. 0.26mol
b. 0.000479mol
c. 1.12mol
Explanation: Please see attachment for explanation