Answer:
Ka = 1.39x10⁻⁶
Explanation:
A monoprotic acid, HX, will be in equilibrium in an aqueous medium such as:
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
<em>Where Ka is:</em>
Ka = [H⁺] [X⁻] / [HX]
<em>Where [] is the molar concentration in equilibrium of each specie.
</em>
The equilibrium is reached when some HX reacts producing H+ and X-, that is:
[HX] = 1.64M - X
[H⁺] = X
[X⁻] = X
As pH is 2.82 = -log [H⁺]:
[H⁺] = 1.51x10⁻³M:
[HX] = 1.64M - 1.51x10⁻³M = 1.638M
[H⁺] = 1.51x10⁻³M
[X⁻] = 1.51x10⁻³M
And Ka is:
Ka = [1.51x10⁻³M] [1.51x10⁻³M] / [1.638M]
<h3>Ka = 1.39x10⁻⁶</h3>
<u>Answer:</u> The density of NaCl solution is 3.930 g/mL
<u>Explanation:</u>
We are given:
Mass of cylinder,
= 21.577 g
Mass of NaCl and cylinder combined, M = 39.664 g
Mass of NaCl,
= 
To calculate density of a substance, we use the equation:

We are given:
Mass of NaCl = 18.087 g
Volume of NaCl solution = 4.602 mL
Putting values in above equation, we get:

Hence, the density of NaCl solution is 3.930 g/mL
Salutations!
What causes a substance to change states of matter?
Energy causes a substance to change states of matter. A matter needs energy to melt, evaporate, boil. Remember: Energy has a sudden change, but the temperature remains absolutely the same. An example of a change in energy is when ice is melting.
Hope I helped (:
Have a great day!
Answer:
they are apart of the life cycle
Explanation: