Answer:
The molar concentration of Cu²⁺ in the initial solution is 6.964x10⁻⁴ M.
Explanation:
The first step to solving this problem is calculating the number of moles of Cu(NO₃)₂ added to the solution:
n = 1.375x10⁻⁵ mol
The second step is relating the number of moles to the signal. We know the the n calculated before is equivalent to a signal increase of 19.9 units (45.1-25.2):
1.375x10⁻⁵ mol _________ 19.9 units
x _________ 25.2 units
x = 1.741x10⁻⁵mol
Finally, we can calculate the Cu²⁺ concentration :
C = 1.741x10⁻⁵mol / 0.025 L
C = 6.964x10⁻⁴ M
Answer:
<em>The correct option is A) Arrhenius</em>
Explanation:
According to the Arrhenius concept of acids and bases, an acid must produce H+ ions when it is present in a solution and the base must produce OH- ions when placed in a solution.
Ammonia does not contain OH- ions of its own when dissolved in water.
The reaction of ammonia dissolving is water can be written as:
NH3 + H2O ⇌ NH4+ + OH−
As we can see from the equation, ammonia does form OH- ions but it does not have OH- ions on its own.
Hence, according to the Arrhenius concept, NH3 is not a base.
Answer: Atomic Nucleus!
Explanation: All atoms have a dense central core called the atomic nucleus. Forming the nucleus are two kinds of particles: protons, which have a positive electrical charge, and neutrons, which have no charge.
(Yes, it was from google.)
You have to put your attention to the unit of concentration. It is expressed in terms of molarity, which is represented in M. It is the number of moles solute per liter solution. So, you simply have to multiply the molarity with the volume in liters.
Volume = 275 mL * 1 L/1000 mL = 0.275 L
<em>Moles Ba(OH)₂ = (0.200 M)(0.275 L) = 0.055 mol</em>
