Chromium exhibits a wide range of possible oxidation states, where the +3 state is the most stable energetically. The +3 and +6 states are the most commonly observed in chromium compounds, whereas the +1, +4 and +5 states are rare.
Answer:
The amount of anhydrous crystal are coming out of the solution when this is cooled from 80°C to 30°C are 5 kg of A
Explanation:
A saturated solution is a chemical solution containing the maximum concentration of a solute dissolved in the solvent, and knowing the solubility of component A at 80°C it is possible to know their amount, thus:
10Kg of water × = 8 kg of A
The maximum concentration that water can dissolve at 30°C is:
10Kg of water × = 3 kg of A
Thus, the amount of anhydrous crystal are coming out of the solution when this is cooled from 80°C to 30°C are:
8 kg of A - 3 kg of A = 5 kg of A
I hope it helps!
Answer:
7
Explanation:
The pH of water is 7.
pH is the convenient scale for expressing the level of acidity or alkalinity of aqueous solutions.
An acidic solution has a pH value less than 7.
As pH decreases, the acidity of solutions increases.
Neutral solutions have a pH of 7.
An alkaline solutions has a pH greater than 7 and the level of alkalinity increases as the pH increases.
Water has a pH of 7 because the concentration of hydrogen and hydroxyl ion is equal.
Answer:
Explanation:
Ba(s) + Mn²⁺ (aq,1M) → Ba²⁺ (aq,1M) + Mn(s)
Ba⁺²(aq) +2e → Ba(s) , E° = −2.90 V
Mn⁺²(aq) +2e → Mn(s), E⁰ =0.80 V
Anode reaction :
Ba(s) → Ba⁺²(aq) +2e E° = −2.90 V
Cathode reaction :
Mn⁺²(aq) +2e → Mn(s) E⁰ =0.80 V
Cell potential = Ecathode - Eanode
Ecell = .80 - ( - 2.90 )
Ecell = 3.7 V .
equilibrium constant ( K ) :
Ecell = .059 log K / n
n = 2
3.7 = .059 log K / 2
log K = 125.42
K = 2.63 x 10¹²⁵ .
Free energy change :
ΔG = - n F Ecell
= - 2 x 96500 x 3.7
= 714100 J
= 7.141 x 10⁵ J .