A chemist is a registered professional who is capable and skilled to carry out experiments in the laboratory which pertains largely to chemicals. The applications which a chemist can do includes A). write a formula for a paint coating, and <span>C).determine the structure of a plant for medical purposes.</span>
Answer:
0.0011 M.
Explanation:
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
w = given mass of KMnO₄ = 0.0908 g
and ,
V = 0.500 L
Since ,
we know ,
m = Molecular mass of KMnO₄ = 158 g/mol
using , the above formula to calculate the moles ,
n = w / m = 0.0908 g / 158 g/mol = 0.00057 mol
now , calculating the molarity as ,
M = n / V = 0.00057 mol / 0.500 L = 0.0011 M.
The reported number of moles will be too low since the additional amount of oxygen is not included. It may be 6 drops but the molarity of the solution is 6M. this meas that for every ml of the JNO3 solution there is 6 moles of JNO3. In every mole of <span>JNO3 there are 3 moles of oxygen. So in every drop of oxygen there are 18 moles of oxygen. </span>
Answer:
pKa = 3.51
Explanation:
The titration of acid solution with NaOH can be illustrated as:
Given that:
Volume of acid solution 
Volume of NaOH 
Molarity of acid solution 
Molarity of NaOH 
For Neutralization reaction:
Making 
the subject of the formula; we have:
However; since the number of moles of NaA formed is equal to the number of moles of NaOH used : Then :
Total Volume after titration = ( 25 + 18.8 ) m
= 43.8 mL
Molarity of salt (NaA ) solution = 
= 
= 0.0429 M
After mixing the two solution ; the volume of half neutralize solution is = 25 mL + 43.8 mL
= 68.8 mL
Molarity of NaA before mixing 
Volume 
Molarity of NaA after mixing 
Volume 
∴
Molarity of acid before mixing = 0.0725 M
Volume = 25 mL
Molarity of acid after mixing = 
= 0.0273 M
Since this is a buffer solution ; then using Henderson Hasselbalch Equation
![pH = pKa + log \frac{[salt]}{[acid]}](https://tex.z-dn.net/?f=pH%20%3D%20pKa%20%2B%20log%20%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D)
![3.51= pKa + log \frac{[0.0273]}{[0.0273]} \\ \\ 3.51= pKa + log \ 1 \\ \\ 3.51= pKa + 0 \\ \\ pKa = 3.51](https://tex.z-dn.net/?f=3.51%3D%20pKa%20%2B%20log%20%5Cfrac%7B%5B0.0273%5D%7D%7B%5B0.0273%5D%7D%20%5C%5C%20%20%5C%5C%203.51%3D%20pKa%20%2B%20log%20%5C%201%20%20%5C%5C%20%5C%5C%203.51%3D%20pKa%20%2B%200%20%5C%5C%20%5C%5C%20pKa%20%3D%203.51)
The nucleus controls and regulates the activities of the cell and carries the genes, structures that contain the hereditary information.
