Answer:
Scale is the right answer
Explanation:
The scale is a sentence that relates distance on the map to distance on Earth
Answer:
no
Explanation:
it is a molecular formula that represents the number atoms and type of atoms
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
Answer:
Explanation:
The halogens have seven electrons in their outermost shell. Each halogen atom lacks a single electron to make their octet a complete one. Elements in the halogen group are univalent and also acceptors of electrons. They are all non-metals and oxidizing agents. The oxidizing power of the halogens decreases from top to down the group. This is why the more powerful halogens displaces a less powerful one from simple salts.
Cl₂ + 2KBr → 2KCl + Br₂
Cl₂ + 2KI → 2KCl + I₂
Br₂ + 2KI → 2KBr + I₂
I₂ + 2KCl → No reaction
Answer: the percent by mass of potassium nitrate is 13.3%
Explanation:
<u>1) Data:</u>
- Mass of solute, m₁ = 45.0 g
- Volume of solvent, V₂ = 295 ml
- density of water, d₂ = 0.997 g/ml
<u>2) Formulae</u>:
- Percent by mass, % = (mass of solute / mass of solution) × 100
- Density, d = mass / volume
<u>3) Solution</u>:
- d = mass / volume ⇒ m₂ = d₂ × V₂ = 0.997 g/ml × 295 ml = 294. g
- mass of solution = m₁ + m₂ = 45.0g + 294. g = 339. g
- % = (45.0 g / 339. g) × 100 = 13.3 %
- The answer has to be reported with 3 significant figures.
