A student weighed out a sample of acid powder and found the mass to be 1.42 g. When the solution turned pink, the student read the burette accurately and found it to be 32.48 mL. If the base concentration is 0.1426 M, what is the molecular weight of the unknown acid

306.6g/mol

Explanation:

To calculate molecular weight you need to know how many grams ou have in a determined amount of moles of substance. As you have the mass of the sample (1.42g), you need to find how many moles are, as follows:

The reaction of the acid HX with the base YOH is:

HX + YOH → H₂O + YX

1 mole of acid reacts per mole of base.

In a titration, the solution turned pink when moles base = moles acid.

Moles of base that the student added (Using the volume and molarity of the solution) are:

32.48mL = 0.03248L ₓ (0.1426 moles base / L) = 0.004632 moles of base

As the titration is in equivalence point, there are 0.004632 moles of the acid

Molecular weight (Ratio between grams of sample and its moles) is:

1.42g / 0.004632 moles =

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.

all eukaryotic cell have mitochondria : )