Answer:
pH = 3.49
Explanation:
We have a buffer system formed by a weak acid (HNO₂) and its conjugate base (NO₂⁻ coming from KNO₂). We can calculate the pH of a buffer ssytem using the Henderson-Hasselbach equation.
pH = pKa + log [base] / [acid]
pH = -log Ka + log [NO₂⁻] / [HNO₂]
pH = -log 4.50 × 10⁻⁴ + log 0.290 M / 0.210 M
pH = 3.49
Answer:
Zero (0)
Explanation:
Since Na^+ has a charge of +1 and Cl^- has a charge of —1 in NaCl
Then the net = +1 —1 = 0
Answer:
<em>The correct option here would be the third one because it is true.
</em>
Explanation:
The diagram shows a bar magnet that has lines that are parallel to each other and are pointing towards one side of the rectangle.
The side of rectangle is South Pole because the arrows that are shown in the diagram are nothing but field lines and these lines tend to start from North Pole and the arrow shows moving inside that point hence that point it would be South Pole showing field lines ending at it.
Following are the chemical elements that have atomic mass greater than 173.5 u and atomic number less than 75.
1. Lutetium
Atomic Number = 71
Atomic Mass = 174.97 u
2. Hafnium
Atomic Number = 72
Atomic Mass = 178.49 u
3. Tantalum
Atomic Number = 73
Atomic Mass = 180.95 u
4. Tungsten
Atomic Number = 74
Atomic Mass = 183.85 u
