Answer:
explain what need to be done here pls? what do you need?
Explanation:
An element is a mixture of two isotopes. One isotope has an atomic mass of 34.969 amu and an abundance of 64.88%. The other isotope has an atomic mass 36.966 amu.
Answer:

Explanation:
Hello there!
In this case, according to the given information, it turns out necessary for us remember that the first-order kinetics is given by:

Whereas the 27.5% complete means A/Ao=0.275, and thus, we solve for the rate constant as follows:

Then, we plug in the variables to obtain:

Regards!
Answer:
35.9 ml
Explanation:
Start with the balanced equation:
3CuCl2(aq)+2Na3PO4(aq)→Cu3(PO4)2(s)+6NaCl(aq)
This tells us that 3 moles of CuCI2 react with 2 moles Na3PO4-
∴ 1 mole CuCl2 will react with 2/3 moles Na3PO4
We know that concentration = moles/volume i.e:
c= n/v
∴n=c×v
∴nCuCl2=0.107×91.01000=9.737×10−3
I divided by 1000 to convert ml to L
∴nNa3PO4=9.737×10−3×23=6.491×10−3
v=nc=6.491×10−30.181=35.86×10−3L
∴v=35.86ml
pH of 0.40M triethylammonium chloride is 5.90.
<h3>What is pH?</h3>
A solution's acidity may be determined by looking at its pH, which is a measurement of hydrogen ion concentration. Pure water slightly separates into ions with roughly equal amounts of hydrogen and hydroxyl (OH) ions. [H+] is 107 for a neutral solution, or pH = 7.
<h3>Given : </h3>
Concentration of triethylammonium chloride = 0.40M
pH = ?
<h3>Solution: </h3>
(CH3CH2)3NHCl ------> (CH3CH2)3NH⁺ + Cl⁻
(CH3CH2)3NH⁺ will react with water to give H3O⁺ .
(CH3CH2)3N will have a Kb = 5.2 x 10 ^(-4)
Kw = Kb x Ka
=> Ka = Kw / Kb = 10^(-14) / 5.2 x 10 ^(-4)
=> Ka = 1.92 x 10^(-11)
so by the reaction we have ,
Ka = x²/(0.40 - x)
=> x = 1.2393 x 10 ^(-6)
now, pH = -log( [H3O⁺]) = - log ( 1.2393 x 10 ^(-6)) = 5.906
To learn more about pH :
brainly.com/question/15289741
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