(c) Cu + S → CuS is classified as a redox reaction
Explanation:
The following reactions are presented:
(a) K₂CrO₄ + BaCl₂ → BaCrO₄ + 2 KCl
(b) Pb²⁺ + 2 Br⁻ → PbBr₂
(c) Cu + S → CuS
Reaction (c) represents a redox reaction, as the oxidation states of the elements are changing. In this case:
Cu + S → CuS
In its elemental form, Cu has an oxidation state of 0, while in CuS (copper sulfide), its oxidation state changes to +2.
Similarly, S in its elemental form has an oxidation state of 0 and is -2 in CuS (copper sulfide).
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redox reactions
Answer:
180.56 kilojoules of heat energy is extracted when 1.00 kg of freon-11 evaporates.
Explanation:
The molar mass of freon-11 is 137.35 g/mol
The enthalpy of vaporization for freon-11 is 24.8 kJ/mol at its normal boiling point of 24°C. Given that,
Mass of freon-11 evaporated = 1.00 kg = 1000 g
Moles of freon-11 evaporated can be calculated as

The energy removed in the form of heat when 1.00 kg of freon-11 vaporizes is:


The problem provides a conversion factor---> 1 mm3= 7.0 x 10^6 RBC. Therefore, to determine the quantity of red blood cells in your sample, we must first convert Liters to cm3 using the conversion factor--> 1 mL= 1 cm3
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What is being removed during the wash is the solvent.
Answer:
Can you rank the following chemical substances in order of their absolute entropies (So) from lowest (1) to highest (5) at a temperature of 298 K?
a. Al (s)
b. H2O (l)
c. HCN (g)
d. CH3COOH (l)
e. C2H6 (g)
Explanation:
Entropy quantifies the level of disorder within a system.
In solids, the entropy is significantly lower compared to liquids and gases.
The typical order of entropy is:
solids < liquids < gases
In the substances listed, liquid water notably exhibits strong intermolecular hydrogen bonding.
This results in water having comparatively lower entropy.
Next in line is acetic acid.
Among the gaseous components, ethane has higher entropy than HCN due to its weaker intermolecular interactions.
HCN involves some hydrogen bonding.
Thus, the order of entropy is:
Al(s) < CH3COOH (l) < H2O(l) < HCN(g) < C2H6(g)