Answer:
K₂Cr₂O₇(s) ⇒ 2 K⁺(aq) + Cr₂O₇²⁻(aq)
Explanation:
Potassium dichromate (K₂Cr₂O₇) is a strong electrolyte, that is, when dissolved in water (the medium), it dissociates in cation potassium (K⁺) and anion dichromate (Cr₂O₇²⁻). The balanced dissociation equation is:
K₂Cr₂O₇(s) ⇒ 2 K⁺(aq) + Cr₂O₇²⁻(aq)
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Answer:
41.17g
Explanation:
We are given the following parameters for Flourine gas(F2).
Volume = 5.00L
Pressure = 4.00× 10³mmHG
Temperature =23°c
The formula we would be applying is Ideal gas law
PV = nRT
Step 1
We find the number of moles of Flourine gas present.
T = 23°C
Converting to Kelvin
= °C + 273k
= 23°C + 273k
= 296k
V = Volume = 5.00L
R = 0.08206L.atm/mol.K
P = Pressure (in atm)
In the question, the pressure is given as 4.00 × 10³mmHg
Converting to atm(atmosphere)
1 mmHg = 0.00131579atm
4.00 × 10³ =
Cross Multiply
4.00 × 10³ × 0.00131579atm
= 5.263159 atm
The formula for number of moles =
n = PV/RT
n = 5.263159 atm × 5.00L/0.08206L.atm/mol.K × 296K
n = 1.0834112811moles
Step 2
We calculate the mass of Flourine gas
The molar mass of Flourine gas =
F2 = 19 × 2
= 38 g/mol
Mass of Flourine gas = Molar mass of Flourine gas × No of moles
Mass = 38g/mol × 1.0834112811moles
41.169628682grams
Approximately = 41.17 grams.
The oxidation number of H is -1.
Sum of the oxidation numbers in each element =
charge of the complex
CaH₂ has 1 Ca atom and 2H atoms. The charge of
the complex is zero. Let’s say Oxidation number of H is "a".
Then,
<span> (+2)
+ 2 x a = 0 </span>
<span> +2 + 2a = 0</span>
2a = -2
a = -1
Hence, the oxidation number of Hydrogen atom in CaH₂ is -1
