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3 years ago

Use the electron-transfer method to balance this equation:

Chemistry

1 answer:

Klio2033 [76]3 years ago

6 0

Answer:

The answer to your question is the letter d.

Explanation:

Data

Zn + HCl ⇒ ZnCl₂ + H₂

- Calculate the Oxidation number of reactants and products

Zn⁰ + H⁺¹Cl⁻¹ ⇒ Zn⁺²Cl₂⁻¹ + H₂⁰

- Determine which elements changed their oxidation numbers

Zn⁰ ⇒ Zn⁺² Zn lost 2e⁻

2H⁺¹ ⇒ H₂⁰ H won 2 e⁻

-Interchange the electrons lost and won

2( Zn⁰ ⇒ Zn⁺²)

2(2H⁺¹ ⇒ H₂⁰)

-Simplify

2Zn⁰ ⇒ 2Zn⁺²

4H⁺¹ ⇒ 2H₂⁰

-Substitute the coefficient in the equation

2Zn + 4HCl ⇒ 2ZnCl₂ + 2H₂

Reactant Element Product

2 Zn 2

4 H 4

4 Cl 4

- Now the reaction is balanced

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When octane (C8H18) is burned in the presence of oxygen, the yield of products (carbon dioxide and water) is 87%. What mass of c

ahrayia [7]

Answer:

14.5g of CO₂ are produced

Explanation:

The reaction of octane with oxygen is:

C₈H₁₈ + 25/2O₂ → 8CO₂ + 9H₂O

Where 1 mole of octane (Molar mass: 114.23g/mol) reacts with 25/2 moles of O₂ (Molar mass 32g/mol) to produce 8 moles of CO₂ and 9 moles of water.

When 21.0 g of octane is burned with 19.0 g of oxygen gas you need to find limiting reactant to find how many moles of products are formed:

Octane: 21.0g ₓ (1mol / 114.23g) = 0.184 moles octane

Oxygen: 19.0g ₓ (1 mol / 32g) = 0.594 moles oxygen

For a complete reaction of 0.184 moles of octane you will need:

0.184 moles C₈H₁₈ ₓ (25/2 moles O₂ / 1 mole C₈H₁₈) = 2.3 moles of oxygen

As you have just 0.594 moles of oxygen, Oxygen is limiting reactant.

Based on chemical equation, 25/2 of O₂ produce 8 moles of CO₂, that means theoretical yield of CO₂ with 0.594 moles of O₂ is:

0.594 moles O₂ ₓ (8 moles CO₂ / 25/2 moles O₂) = 0.380 moles of CO₂

But, as yield of products is 87%, moles produced of CO₂ are:

0.380 moles of CO₂ ₓ 87% = 0.331 moles CO₂ are produced.

As molar mass of CO₂ is 44g/mol, mass of CO₂ in 0.331 moles is:

0.331 moles CO₂ ₓ (44g / mol) =

<h3>14.5g of CO₂ are produced</h3>

6 0

3 years ago

Why must power plants spend so much money and be so cautious in dealing with these materials?

shepuryov [24]

If you are referring to nuclear power plants and radioactive materials, then there is a high necessity to be cautious and stay safe because only by being safe you can prevent accidents like those caused in Ukraine and Japan. Unlike other types of power plants whose destruction in case of an accident can relatively easily be contained, nuclear power plants are extremely difficult to manage if things go out of hand since you can destroy the air around it, the water, the food by ruining the soil, and many other things.

8 0

3 years ago

fish give off the compound ammonia which has a pH above 7 to which class of compounds does ammonia belong

jasenka [17]

Answer:
The compound ammonia given by fish is alkaline

Explanation:
We can classify elements/compounds based on their pH values into three types:
acids: these are compounds having pH value lower than 7
neutral: these are compounds having pH value equal to 7
alkalies: these are compounds having pH values higher than 7

This is shown in the attached image

We are given that the pH of the compound ammonia generated by the fish is above 7.
According to the above explanation, compound ammonia would be an alkaline compound.

Hope this helps :)

5 0

3 years ago

Stoichiometric calculations are based on balanced chemical equations. the reason that chemical equations must always be balanced

Roman55 [17]

Answer: Chemical equations are balanced in order to: 1) satisfy the Law of Conservation of Mass, and 2) establish the mole relationships needed for stoichiometric calculations. The Law of Conservation of Mass: The Law of Conservation of Mass states that mass cannot be created or destroyed.

6 0

4 years ago

What is the pH of a 6.7 x 10^−5 M H+ solution?

lyudmila [28]

Answer:

pH = 4.17

Explanation:

According to the molar concentration you stated, pH of the solution is: 4.17

Remember that pH = - log [H⁺]

and [H⁺] = 10^-pH

When:

pH > 7 → Basic solution

pH = 7 → Neutral solution

pH < 7 → Acid solution

3 0

3 years ago

Read 2 more answers