All categories

2 years ago

An alkaline battery produces electrical energy according to this balanced equation:

1 answer:

6 0

Considering the reaction stoichiometry and the definition of limiting reagent, the correct answer is option D. MnO₂; 17.2 grams Zn(OH)₂.

The balanced reaction is:

Zn + 2 MnO₂ + H₂O → Zn(OH)₂ + Mn₂O₃

<h3>Reaction stoichiometry</h3>

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Zn: 1 mole
MnO₂: 2 moles
H₂O: 1 mole
Zn(OH)₂: 1 mole
Mn₂O₃: 1 mole

The molar mass of the compounds present in the reaction is:

Zn: 65.37 g/mole
MnO₂: 86.94 g/mole
H₂O: 18 g/mole
Zn(OH)₂: 99.37 g/mole
Mn₂O₃: 157.88 g/mole

Then, by reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of mass of each compound participate in the reaction:

Zn: 1 mole× 65.37 g/mole= 65.37 grams
MnO₂: 2 moles× 86.94 g/mole= 173.88 grams
H₂O: 1 mole× 18 g/mole= 18 grams
Zn(OH)₂: 1 mole× 99.37 g/mole= 99.37 grams
Mn₂O₃: 1 mole× 157.88 g/mole= 157.88 grams

<h3>Limiting reagent</h3>

The limiting reagent is one that is consumed first in its entirety, determining the amount of product in the reaction. When the limiting reagent is finished, the chemical reaction will stop.

To determine the limiting reagent, it is possible to use a simple rule of three as follows: if by stoichiometry 65.37 grams of Zn reacts with 173.88 grams of MnO₂, 25 grams of Zn reacts with how much mass of MnO₂?

$mass of MnO_{2} =\frac{25 grams of Znx173.88 grams of MnO_{2}}{65.37 grams of Zn}$

mass of MnO₂ = 66.498 grams

But 66.498 grams of MnO₂ are not available, 30 grams are available. Since you have less mass than you need to react with 25 grams of Zn, MnO₂ will be the limiting reagent.

<h3>Mass of Zn(OH)₂ produced</h3>

Then, it is possible to determine the Mass of Zn(OH)₂ produced by another rule of three, considering the limiting reactant: if by stoichiometry 173.88 grams of MnO₂ produce 99.37 grams of Zn(OH)₂, if 30 grams of MnO₂ react how much mass of Zn(OH)₂ will be formed?

$mass of Zn(OH)_{2}=\frac{30 grams of MnO_{2}x99.37 grams of Zn(OH)_{2} }{173.88 grams of MnO_{2}}$

mass of Zn(OH)₂= 17.14 grams≅ 17.2 grams

In summary, the mass of Zn(OH)₂ that is produced when 25 grams of Zn react with 30 grams of MnO₂ is 17.2 grams.

<h3>Summary</h3>

In summary, the correct answer is option D. MnO₂; 17.2 grams Zn(OH)₂.

Learn more about reaction stoichiometry:

brainly.com/question/11999193

brainly.com/question/15111313?referrer=searchResults

brainly.com/question/6061451?referrer=searchResults

You might be interested in

Predict the products of La(s) + O2(aq) ->

mina [271]

Answer:

i. La (s) + O2 (g) => LaO2 (s)

ii. La (s) + O2 (g) => La2O (s)

III. La (s) + O2 (g) => La2O3 (s)

Explanation:

Hello there!

When you are given such a problem for completing the chemical equations, what you have to understand is that metals are found in groups I, II and III. While Oxygen is a group VI element.

From the above question I have considered that my La(s), solid is either Sodium (Na) - group I, Magnesium - group II and Aluminum - group III.

In a reaction, there is exchange of electrons given by their oxidation numbers (I, II and III - for our metals above)

The chemical equations are thus;

i. Na (s) + O2 (g) => NaO (s)

ii. Mg (s) + O2 (g) => Mg2O (s)

iii. Al (s) + O2 (g) => Al2O3 (s)

Relate this to the problem and it will be;

i. La (s) + O2 (g) => LaO2 (s)

ii. La (s) + O2 (g) => La2O (s)

III. La (s) + O2 (g) => La2O3 (s)

I hope this helps you to understand better. Enjoy your studies

3 0

2 years ago

Alkali metals

Evgen [1.6K]

The answer is going to be A.

3 0

3 years ago

Read 2 more answers

7. If all of the forces on an object are balanced, the object?

dolphi86 [110]

Answer:

Is balanced

Explanation:

4 0

3 years ago

The emission spectrum of hydrogen shows discrete, bright, colored lines. Which characteristic of the Bohr model is best supporte

natali 33 [55]

The characteristic of the Bohr model that would best support his observation is this assumption: "The energy of the electron in an orbit is proportional to its distance from the nucleus. The further the electron is from the nucleus, the more energy it has." The discrete, bright, colored lines might represent the electrons and its distance from the nucleus. The lights are caused by the energy it has.

7 0

3 years ago

Read 2 more answers

HELP!!!! The freezing of methane is an exothermic change. What best describes the temperature conditions that are likely to make

vazorg [7]

Answer: The correct statement is low temperature only, because entropy decreases during freezing.

Explanation:

The relationship between Gibb's free energy, enthalpy, entropy and temperature is given by the equation:

$\Delta G=\Delta H-T\Delta S$

Where,

$\Delta G$ = change in Gibb's free energy

$\Delta H$ = change in enthalpy

T = temperature

$\Delta S$ = change in entropy

It is given that freezing of methane is taking place, which means that entropy is decreasing and $Delta S$ is becoming negative. It is also given that the reaction is an exothermic reaction, this means that the $\Delta H$ is also negative.

For a reaction to be spontaneous, $\Delta G$ must be negative.

$-ve=-ve-[T(-ve)]\\\\-ve=-ve+T$

From above equations, it is visible that $\Delta G$ will be negative only when the temperature will be low.

Hence, the correct statement is low temperature only, because entropy decreases during freezing.

8 0

3 years ago