Question 16 A chemistry graduate student is given of a methylamine solution. Methylamine is a weak base with . What mass of should the student dissolve in the solution to turn it into a buffer with pH ? You may assume that the volume of the solution doesn't change when the is dissolved in it. Be sure your answer has a unit symbol, and round it to significant digits.

90 g CH₃NH₃Cl

Explanation:

It appears your question lacks the values required to solve this problem. However, an online search tells me these are the values. Be aware if your values are different your answer will also be different, but the methodology remains the same.

" A chemistry graduate student is given 450 mL of a 1.70 M methylamine solution. Methylamine is a weak base with Kb=4.4x10⁻⁴. What mass of CH₃NH₃Cl should the student dissolve in the methylamine solution to turn it into a buffer with pH = 10.40 ? You may assume that the volume of the solution doesn't change when the is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. "

We'll use the Henderson-Hasselbach equation:

So first we use Kb to calculate Ka and then pKa:

Now we can calculate the concentration of the salt, CH₃NH₃Cl:

Now we use the final volume to calculate the moles of CH₃NH₃Cl and finally its mass, using its molecular weight:

Which when rounded to 2 significant digits becomes 90 g CH₃NH₃Cl

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.

the answer is 1260

you spend 7 hours in school for 1 school day with 5 school days in 1 school week with 36 school weeks in a school year.

7*5*36= 1260 it's all about multiplying