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3 years ago

Which statement is true if the Hrxn of a reaction is positive?

Chemistry

2 answers:

erma4kov [3.2K]3 years ago

7 0

I think it is b..................................................

iren2701 [21]3 years ago

3 0

Answer: The correct answer is Option A.

Explanation:

Endothermic reactions are defined as the reactions in which potential energy of the reactants is less than the potential energy of the products. The total enthalpy change of the reaction $(\Delta H_{rxn})$ comes out to be positive. Energy is absorbed during this reaction.

$\Delta H_{rxn}=\Delta H_{products}-\Delta H_{reactants}=+ve$

Exothermic reactions are defined as the reactions in which potential energy of the products is less than the potential energy of the reactants. The total enthalpy change of the reaction $(\Delta H_{rxn})$ comes out to be negative. Energy is released during this reaction.

$\Delta H_{rxn}=\Delta H_{products}-\Delta H_{reactants}=-ve$

From the above information, the correct answer is Option A.

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Question 6 the chemical formula ch2o can be classified as: empirical only. molecular only. empirical, possibly molecular. not en

frosja888 [35]

The chemical formula CH2O can be classified as Empirical formula and possibly a molecular formula. The empirical formula of a compound is the simplest formula that indicates the simplest ratio of atoms in the compound, while the molecular formula is the representation of the actual whole number ratio between the elements of the compound.

6 0

3 years ago

Enough of a monoprotic acid is dissolved in water to produce a 1.64 M solution. The pH of the resulting solution is 2.82 . Calcu

Lady bird [3.3K]

Answer:

Ka = 1.39x10⁻⁶

Explanation:

A monoprotic acid, HX, will be in equilibrium in an aqueous medium such as:

HX(aq) ⇄ H⁺(aq) + X⁻(aq)

Where Ka is:

Ka = [H⁺] [X⁻] / [HX]

Where [] is the molar concentration in equilibrium of each specie.

The equilibrium is reached when some HX reacts producing H+ and X-, that is:

[HX] = 1.64M - X

[H⁺] = X

[X⁻] = X

As pH is 2.82 = -log [H⁺]:

[H⁺] = 1.51x10⁻³M:

[HX] = 1.64M - 1.51x10⁻³M = 1.638M

[H⁺] = 1.51x10⁻³M

[X⁻] = 1.51x10⁻³M

And Ka is:

Ka = [1.51x10⁻³M] [1.51x10⁻³M] / [1.638M]

6 0

3 years ago

The molar mass of aniline is 93 g/mol. what is its molecular formula

Mashutka [201]

Answer:

Molecular formula of aniline is C6H5NH2.

Explanation:

As we know, molecular mass can be calculated as

Molar mass = C6H5NH2

Molar mass = (6*12)+(1*7)+(28)

Molar mass = 93 g/mol

4 0

3 years ago

Why are carbon and nitrogen essential for survival to all living organisms? A.

bagirrra123 [75]

Hello there.

Why are carbon and nitrogen essential for survival to all living organisms?

They are needed to release the energy stored in food.
Therefore, The correct answer would be Option B.

3 0

3 years ago

Read 2 more answers

2NO + 3MnO2 + 4H â 2NO3- + 3Mn2 + 2H2O For the above redox reaction, assign oxidation numbers and use them to identify the eleme

mixer [17]

Answer:

Manganese decreases from 4+ to 2+ (reduced and oxidizing agent) and nitrogen increases from 2+ to 5+ (oxidized and reducing agent).

Explanation:

Hello there!

In this case, according to the given redox reaction, we rewrite it as a convenient first step:

$2NO + 3MnO_2 + 4H^+ \rightarrow 2NO_3^- + 3Mn^{2+} + 2H_2O$

Next, we assign the oxidation numbers as follows:

$2N^{2+}O^{2-} + 3Mn^{4+}O^{-2}_2 + 4H^+ \rightarrow 2(N^{5+}O^{2-}_3)^- + 3Mn^{2+} + 2H^+_2O^{2-}$

Thus, we can see that both manganese and nitrogen undergo a change in their oxidation number, the former decreases from 4+ to 2+ (reduced and oxidizing agent) and the latter increases from 2+ to 5+ (oxidized and reducing agent).

Regards!

4 0

2 years ago