Answer:
He needs to add 4 mL of the 0.5 M solution to 6 mL of water.
The pH value of the solution is mathematically given as
pH=2.35
<h3>What
pH value of the
solution?</h3>
Question Parameters:
pH during the titration of 20.00 mL of 0.1000 M dimethylamine,
with 0.1000 M HCl(aq) after 21.23 mL of the acid
Generally, the equation for the Chemical Reaction is mathematically given as
(CH3)2NH(aq), +Hcl ---> <---- (CH3)2NH2Cl(aq)
Therefore

HCL=0.00444M
WHere
HClaq--->H+(aq)+Cl-(aq)
Hence
H+=0.00444M
pH= -log{H+}
pH=log(0.00444)
pH=2.35
For more information on Chemical Reaction
brainly.com/question/11231920
Answer:
they must have same atomic number and different atomic mass
The three factors determine the chemical properties of an element:
<span><span>The number and arrangement of electrons in an atom
</span><span>The number of valence electrons
</span><span>The number and arrangement of electrons</span></span>