The correct answer among the choices given is option B. Radioisotopes are isotopes that emit radiation because they have unstable nuclei. These are radioactive isotopes of an element. They are defined as atoms that contain an unstable combination of neutrons and protons.
Answer:
1. B 2. C 3. B or C 4. A 5. A
C, im pretty sure if im wrong my bad
The statement that true about the temperature of a gas is at <span> a higher temperature, the particles have a higher average kinetic energy. The rest of the choices do not answer the question above.</span>
Answer:
1.85 g
Explanation:
The strategy here is to utilize the Henderson-Hasselbach equation
pH = pKa + log [A⁻] / [HA]
to calculate the ratio log [A⁻] / [HA], and from there to calculate the concentration [A⁻] and finally the mass of NaNO₂ from the number of moles assuming the final buffer volume is 50.0 mL ( that is the volume does not change by the addition of NaNO₂)
pH = pKa + log [NO₂⁻]/[HNO₂]
3.13 = 3.40 + log [NO₂⁻]/[HNO₂]
- 0.27 = log [NO₂⁻]/[HNO₂]
taking the inverse log function to both sides of this equation
0.54 = [NO₂⁻]/[HNO₂]
Now [HNO₂] = 1.0 M, therefore [NO₂⁻] = [NaNO₂] =
0.54 x 1.0 M = 0.54 M
from M = mol / L we get
mol = 0.54 mol/L x 0.050L = 0.027 mol
the molar mass of NaNO₂ is = 68.99 g / mol, so the mass of 0.027 mol is
0.027 mol x 68.99 g/mol = 1.85 g
