Answer:
what is this I am not getting which type of this question you have taken from where
Electromagnetic Radiation. Do you listen to the radio, watch TV, or use a microwave oven? All these devices make use of electromagnetic waves. Radio waves, microwaves, visible light, and x rays are all examples of electromagnetic waves that differ from each other in wavelength.
The volume of the textbook calculated by the student written to 3 significant figures is 992cm³
- According to this question, a student calculates the volume of his textbook and arrived at an answer of 991.880 cm³.
- To round up this digit to 3 significant figures, which means that only 3 significant numbers should appear in the answer.
- To do this, the number after the third number is 8, which means we can round up the value of 1 to 2. Hence, the volume of the textbook calculated by the student is 992cm³ in 3 s.f.
Learn more at: brainly.com/question/16563962?referrer=searchResults
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>
