(a)
Interpretation:
The balanced chemical equation for the given reaction between hydrazine and oxygen also the oxidizing and reducing agents in the reaction should be identified.
Concept introduction:
Chemical equation is the representation of a chemical reaction, in which the reactants and products of the reactions are represented left and right side of an arrow respectively by using their respective chemical formulas.
Reactant of a chemical reaction is the substrate compounds or the compounds which undergo a chemical reaction.
Product of a chemical reaction is the produced compounds or the compounds formed after a chemical reaction.
Balanced chemical equation of a reaction is written according to law of conservation of mass.
Stoichiometry of a chemical reaction is the relation between reactants and products of the reaction and it is represented by the coefficients used for the reactants and products involved in the chemical equation.
The hot water system can corrode because of the presence of dissolved oxygen in water. This dissolved oxygen leads to corrosion. However, this oxygen can be removed from water with the use of hydrazine. The formula for hydrazine is
(a)
Answer to Problem 79SCQ
The balanced chemical equation for the reaction of hydrazine and oxygen is,
Oxygen is oxidising agent and hydrazine is a reducing agent.
Explanation of Solution
The formula for hydrazine is
The balanced chemical equation for the reaction of hydrazine and oxygen is,
Oxygen acts as an oxidising agent in the reaction and changes its oxidation number from
(b)
Interpretation:
The value of
Concept introduction:
The Gibbs free energy or the free energy change is a
The sign of
The sign of
(b)
Answer to Problem 79SCQ
The value of
The value of
The value of
Explanation of Solution
The value of
Given:
Refer to Appendix L for the values of standard entropies and enthalpies.
The standard entropy value for
The standard entropy value for
The standard entropy value for
The standard entropy value for
The standard enthalpy value for
The standard enthalpy value for
The standard enthalpy value for
The standard enthalpy value for
The given reaction is,
The standard enthalpy change is,
Substitute the values,
The standard entropy change is,
Substitute the values,
Now,
Substitute the value of
(c)
Interpretation:
The change in temperature expected in heating system that has
Concept introduction:
The Gibbs free energy or the free energy change is a thermodynamic quantity represented by
The sign of
The sign of
(c)
Answer to Problem 79SCQ
The temperature change expected in a heating system containing
Explanation of Solution
The temperature change expected in a heating system containing
Given:
The value of
Thus, one mole of hydrazine releases
The density of water is
The specific heat
The heat of the system is related to specific heat and temperature by the expression,
Substitute the values,
(d)
Interpretation:
The amount of
Concept introduction:
Moles: One mole is equivalent to the mass of the substance consists same number of units equal to the atoms present in
From given mass of substance moles could be calculated by using the following formula,
(d)
Answer to Problem 79SCQ
The number of moles of
Explanation of Solution
The number of moles of
Given:
The solubilty of oxygen is in water at
Thus, the number of moles
(e)
Interpretation:
The mass of solution that has
Concept introduction:
Moles: One mole is equivalent to the mass of the substance consists same number of units equal to the atoms present in
From given mass of substance moles could be calculated by using the following formula,
Mass: It is the quantitative measure of a substance. The amount of matter present in substance is expressed as mass. The
(e)
Answer to Problem 79SCQ
The mass of hydrazine solution that should be added to totally consume the dissolved oxygen is
Explanation of Solution
The mass of hydrazine solution that should be added to totally consume the dissolved oxygen is calculated below.
Given:
Hydrazine is available as
The number of moles of oxygen present is
Thus the mass
(f)
Interpretation:
The volume of
Concept introduction:
Moles: One mole is equivalent to the mass of the substance consists same number of units equal to the atoms present in
From given mass of substance moles could be calculated by using the following formula,
Mass: It is the quantitative measure of a substance. The amount of matter present in substance is expressed as mass. The
(f)
Answer to Problem 79SCQ
The volume of
Explanation of Solution
The volume of
Given:
The given reaction is,
Thus,
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Chapter 18 Solutions
Chemistry & Chemical Reactivity
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