21.69mL - 20.70mL = .99mL Fe
7.8 g / .99 mL = 7.9g/mL
Hey there!:
HCl + MnO2 → MnCl2 + H2O + Cl2
* in HCl the oxidation state of Cl is -1 .
* on the product side the oxidation state is 0 .
* therefore Cl gains electrons .
* in MnO2 the oxidation state of Mn is +4
* in MnCl2 the oxidation state of Mn is +2
Therefore Mn loses electrons
Answer A
Hope That helps!
Answer:
Na has the most similar configuration.
Explanation:
Na electron configuration: 1s²2s²2p⁶3s¹ or [Ne] 3s₁
Mg electron configuration: 1s²2s²2p⁶3s² or [Ne] 3s²
Be electron configuration: 1s²2s² or [He] 2s²
This is because Na and Mg are right next to each other in the same period (horizontal).
Answer:
11%
Explanation:
1) Calculate van 't Hoff factor:
Δt = i Kf m
0.31 = i (1.86) (0.15)
i = 1.111
2) Calculate value for [H+]:
CCl3COOH ⇌ H+ + CCl3COO¯
total concentration of all ions in solution equals:
(1.11) (0.15) = 0.1665 m
This is a molality, but we will act as if it a molarity since we will assume the density of the solution is 1.00 g/cm3, which makes the molarity equal to the molality.
0.1665 = (0.15 − x) + x + x
x = 0.0165 M
3) Calculate the percent dissociation:
0.0165/ 0.15 = 11 %
