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3 years ago

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Tollens’ test, also known as silver-mirror test, is a qualitative laboratory test used to distinguish between an aldehyde and a

ketone. It exploits the fact that aldehydes are readily oxidized (see oxidation),
whereas ketones are not.
Tollens’ test uses a reagent known as Tollens’ reagent,
which is a colorless,
basic,
aqueous solution containing silver ions coordinated to ammonia [Ag(NH3)2+].
It is prepared using a two-step procedure.

1 answer:

Makovka662 [10]3 years ago

3 0

Explanation:

Tollens' reagent is prepared by using two-step process : -

Step 1:

Silver oxide is formed by mixing aqueous silver nitrate with base like sodium hydroxide. The reaction is shown below as:

$AgNO_3 + NaOH &\rightarrow AgOH + NHO_3 \nonumber \\ 2AgOH &\rightarrow Ag_2O + H_2O$

Step 2

Ammonia solution is drop-wise added until all the silver oxide dissolves to form the reagent. The reaction is shown below as:

$Ag_2O + 4NH_3 + H_2O \rightarrow 2Ag(NH_3)_2^+ + 2OH^-$

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Sulfuryl dichloride is formed when sulfur dioxide reacts with chlorine.

zubka84 [21]

<u>Answer:</u> The value of $\Delta G^o$ of the reaction is 28.38 kJ/mol

<u>Explanation:</u>

For the given chemical reaction:

$SO_2(g)+Cl_2(g)\rightarrow SO_2Cl_2(g)$

The equation used to calculate enthalpy change is of a reaction is:

$\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f_{(product)}]-\sum [n\times \Delta H^o_f_{(reactant)}]$

The equation for the enthalpy change of the above reaction is:

$\Delta H^o_{rxn}=[(1\times \Delta H^o_f_{(SO_2Cl_2(g))})]-[(1\times \Delta H^o_f_{(SO_2(g))})+(1\times \Delta H^o_f_{(Cl_2(g))})]$

We are given:

$\Delta H^o_f_{(SO_2Cl_2(g))}=-364kJ/mol\\\Delta H^o_f_{(SO_2(g))}=-296.8kJ/mol\\\Delta H^o_f_{(Cl_2(g))}=0kJ/mol$

Putting values in above equation, we get:

$\Delta H^o_{rxn}=[(1\times (-364))]-[(1\times (-296.8))+(1\times 0)]=-67.2kJ/mol=-67200J/mol$

The equation used to calculate entropy change is of a reaction is:

$\Delta S^o_{rxn}=\sum [n\times \Delta S^o_f_{(product)}]-\sum [n\times \Delta S^o_f_{(reactant)}]$

The equation for the entropy change of the above reaction is:

$\Delta S^o_{rxn}=[(1\times \Delta S^o_{(SO_2Cl_2(g))})]-[(1\times \Delta S^o_{(SO_2(g))})+(1\times \Delta S^o_{(Cl_2(g))})]$

We are given:

$\Delta S^o_{(SO_2Cl_2(g))}=311.9J/Kmol\\\Delta S^o_{(SO_2(g))}=248.2J/Kmol\\\Delta S^o_{(Cl_2(g))}=223.0J/Kmol$

Putting values in above equation, we get:

$\Delta S^o_{rxn}=[(1\times 311.9)]-[(1\times 248.2)+(1\times 223.0)]=-159.3J/Kmol$

To calculate the standard Gibbs's free energy of the reaction, we use the equation:

$\Delta G^o_{rxn}=\Delta H^o_{rxn}-T\Delta S^o_{rxn}$

where,

$\Delta H^o_{rxn}$ = standard enthalpy change of the reaction =-67200 J/mol

$\Delta S^o_{rxn}$ = standard entropy change of the reaction =-159.3 J/Kmol

Temperature of the reaction = 600 K

Putting values in above equation, we get:

$\Delta G^o_{rxn}=-67200-(600\times (-159.3))\\\\\Delta G^o_{rxn}=28380J/mol=28.38kJ/mol$

Hence, the value of $\Delta G^o$ of the reaction is 28.38 kJ/mol

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3 years ago

Write a balanced equation for its combustion reaction.

laila [671]

<h3>Answer:</h3>

C₅H₁₂O(l)+15/2O₂(g)→5CO₂(g)+6H₂O(l)

<h3>Explanation:</h3>

The balanced chemical equation for the combustion of the hydrocarbon in question is;

C₅H₁₂O(l)+15/2O₂(g)→5CO₂(g)+6H₂O(l)

A balanced chemical equation is one in which the number of atoms of each element is equal on both sides of the equation.

In this case;

Reactant side has; 5 carbon atoms, 12 hydrogen atoms and 16 Oxygen atoms
Product side has; 5 carbon atoms, 12 hydrogen atoms and 16 Oxygen atoms

An equation is balanced by putting appropriate coefficients on reactants and products involved in the reaction.
An equation is balanced so as to obey the law of conservation of mass.

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3 years ago

Which of the following species has the greatest

Licemer1 [7]

Answer: Option (3) is the correct answer.

Explanation:

When there is a negative charge on an atom then we add the charge with the number of electrons. Whereas when there is a positive charge on an atom then we subtract the charge from the number of electrons.

Atomic number of chlorine is 17. So, number of electrons present in $Cl^{-}$ is 17 + 1 = 18 electrons.

Atomic number of cobalt is 27. So, number of electrons present in $Co^{4+}$ is 27 - 4 = 23 electrons.

Atomic number of iron is 26. So, number of electrons present in $Fe^{2+}$ is 26 - 2 = 24 electrons.

Atomic number of vanadium is 23. So, number of electrons present in V is 23 electrons.

Atomic number of scandium is 21. So, number of electrons present in $Sc^{2-}$ is 21 + 2 = 23 electrons.

Thus, we can conclude that out of the given species, $Fe^{2+}$ has the greatest number of electrons.

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kirill [66]

Answer:

Yes

Explanation:

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aliya0001 [1]

Answer:

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Explanation:

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