Complete Question:
In the first paragraph, the words “disrobed,” “unveiling” and “deconstructed” primarily serve to (a) highlight the negative connotations that laser technology currently has, (b) emphasize the extensive reach of laser technology; (c) demonstrate the inherently unknowable characteristics of objects, even with laser technology; (d) implicitly compare lasers to other forms of technology
Answer:
(b) emphasize the extensive reach of laser technology;
Explanation:
The use of the word disrobed and deconstructed from the passage emphasizes the extensive reach of laser technology. Even without looking up the dictionary meaning of the two words, one can easily deduce that the passage is a pro-laser technology one.
- The passage presents the use of the laser technology in solar exploration.
- It also show its use by ecologists.
#learnwithBrainly
Answer:
Incomplete question
Complete question:
8. Compartments A and B are separated by a membrane that is permeable to K+ but not to Na+ or Cl-. At time zero, a solution of KCl is poured into compartment A and an equally concentrated solution of NaCl is poured into compartment B. Which would be true once equilibrium is reached?
A. The concentration of Na+ in A will be higher than it was at time zero.
B. Diffusion of K+ from A to B will be greater than the diffusion of K+ from B to A.
C. There will be a potential difference across the membrane, with side B negative relative to side A.
D. The electrical and diffusion potentials for K+ will be equal in magnitude and opposite in direction.
E. The concentration of Cl- will be higher in B than it was at time zero.
Answer: D. The electrical and diffusion potentials for K+ will be equal in magnitude and opposite in direction.
Explanation:
Diffusion is the movement of molecules from region of higher concentration to lower concentration through a semipermeable membrane.
Since the k+ is the permeable membrane, the k+ ion in the KCl would move in equal magnitude and direction in the solution.
a.
Acids react with bases and give salt and water and the products.
Hence, HCl reacts with NaOH and gives NaCl salt and H₂O as the products. The reaction is,
HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l)
To balance the reaction equation, both sides hould have same number of elements.
Left hand side, Right hand side,
H atoms = 2 H atoms = 2
Cl atoms = 1 Cl atoms = 1
Na atoms = 1 Na atoms = 1
O atoms = 1 O atoms = 1
Hence, the reaction equation is already balanced.
b.
Molarity (M)= moles of solute (mol) / Volume of the solution (L)
HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l)
Molarity of NaOH = <span>0.13 M
</span>Volume of NaOH added = <span>43.7 mL
Hence, moles of NaOH added = 0.13 M x 43.7 x 10</span>⁻³ L
= 5.681 x 10⁻³ mol
Stoichiometric ratio between NaOH and HCl is 1 : 1
Hence, moles of HCl = moles of NaOH
= 5.681 x 10⁻³ mol
5.681 x 10⁻³ mol of HCl was in <span>26.9 mL.
Hence, molarity of HCl = </span>5.681 x 10⁻³ mol / 26.9 x 10⁻³ L
= 0.21 M
This problem handles<em> boiling-point elevation</em>, which means we will use the formula:
ΔT = Kb * m
Where ΔT is the difference of Temperature between boiling points of the solution and the pure solvent (Tsolution - Tsolvent). Kb is the ebullioscopic constant of the solvent (2.64 for benzene), and m is the molality of the solution.
Knowing that benzene's boiling point is 80.1°C, we <u>solve for m</u>:
Tsolution - Tsolvent = Kb * m
80.23 - 80.1 = 2.64 * m
m = 0.049 m
We use the definition of molality to <u>calculate the moles of azulene</u>:
0.049 m = Xmoles azulene / 0.099 kgBenzene
Xmoles azulene = 4.87 x10⁻³ moles azulene
We use the mass and the moles of azulene to<u> calculate its molecular weight</u>:
0.640 g / 4.875 x10⁻³ mol = 130.28 g/mol
<em>A molecular formula that would fulfill that molecular weight</em> is C₁₀H₁₀. So that's the result of solving this problem.
The actual molecular formula of azulene is C₁₀H₈.
Answer:
<h3>The answer is option B</h3>
Explanation:
The pH of a solution can be found by using the formula
pH = - log [ H+ ]
To find the hydrogen ion concentration substitute the pH into the above formula and solve for the [ H+ ]
From the question
pH = 4.25
So we have
4.25 = - log [ H+ ]
<u>Find the antilog of both sides</u>
That's
<h3>
![[ H+ ] = {10}^{ - 4.25}](https://tex.z-dn.net/?f=%5B%20H%2B%20%5D%20%3D%20%20%7B10%7D%5E%7B%20-%204.25%7D%20)
</h3>
We have the final answer as
<h2>
![[ H+ ] = 5.6 \times {10}^{ - 5} \: M](https://tex.z-dn.net/?f=%5B%20H%2B%20%5D%20%3D%205.6%20%5Ctimes%20%20%7B10%7D%5E%7B%20-%205%7D%20%20%5C%3A%20M)
</h2>
Hope this helps you
