The area of the gold electrodes on the quartz crystal microbalance at the opening of Chapter 2 is 3.3 mm^2. One gold electrode is covered with DNA at a surface density of 1.2 pmol/cm2. (a) How much mass of the nucleotide cytosine (C) is bound to the surface of the electrode when each bound DNA is elongated by one unit of C

This question is incomplete, the complete question is;

The area of the gold electrodes on the quartz crystal microbalance at the opening of Chapter 2 is 3.3 mm^2. One gold electrode is covered with DNA at a surface density of 1.2 pmol/cm2.

(a) How much mass of the nucleotide cytosine (C) is bound to the surface of the electrode when each bound DNA is elongated by one unit of C. The mass formula mass of the bound nucleotide is cytosine + deoxyribose + phosphate = C9H10N3O6P = 287.2 g/mol

mass of the nucleotide (c) bound is 11.37 g

Explanation:

Given that the area of gold electrodes = 3.3 mm^2

surface density of one gold electrode = 1.2 pmol/cm^2

that is to that in every 1 cm^2 of area, 1.2 pmol DNA is present

therefore

mass of nucleotide present in 3.3 mm^2 is;

= (1.2/100 * 3.3) pmol

= 0.0396 pmol

we were given that formula mass of the bound nucleotide = 287.2 g/mol

so

mass of the nucleotide (c) bound = ( 287.2 * 0.0396 )g

mass of the nucleotide (c) bound =  11.37 g

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.