I don't understand with the question number 4, does anybody understand how to do it?

A car engine produces 604 kJ of mechanical energy from fuel capable of producing 2416 kJ of energy, then efficiency of the engine is 25%.

We can calculate the efficiency by using the below equation as:

Efficiency = (Actual production / Theoretical production) × 100%

Given that,

Actual production = 604 kJ

Theoretical production = 2,416 kJ

On putting values in given equation, we get

Efficiency = (604/2,416) × 100% = 25%

Hence efficiency of the engine is 25%.

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Explanation:

According to the law of conservation of mass, mass can neither be created nor destroyed but it can simply be transformed from one form to another.

For example, [tex]Na^{+} + Cl^{-} \rightarrow NaCl[/tex]

Mass of Na = 23 g/mol

Mass of Cl = 35.5 g/mol

Sum of mass of reactants = mass of Na + mass of Cl

= 23 + 35.5 g/mol

= 58.5 g/mol

Mass of product formed is as follows.

Mass of NaCl = mass of Na + mass of Cl

= (23 g/mol + 35.5) g/mol

= 58.5 g/mol

As mass reacted is equal to the amount of mass formed. This shows that mass is conserved.

As a result, law of conservation of mass is obeyed.

Explanation:

A physical change, such as a state change or dissolving, does not create a new substance, but a chemical change does.

In a chemical reaction, the atoms and molecules that interact with each other are called reactants.

In a chemical reaction, the atoms and molecules produced by the reaction are called products.

In a chemical reaction, only the atoms present in the reactants can end up in the products. No new atoms are created, and no atoms are destroyed.

In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.

Answer:

It is B

Explanation:

The formation of water is a chemical reaction which rearranges atoms. The other reactions are nuclear reactions.

Answer:

216 g of NO

Explanation:

We begin from the reaction:

4NH₃ + 5O₂ →  4NO  + 6H₂O

We determine the limiting reactant with the moles of each reactant:

4 moles of ammonia react to 5 moles of oxygen

Our 7.2 moles of ammonia may react to (7.2 . 5) /4 = 9 moles

It's ok because we have 9.6 moles of oxygen. 0.6 moles still remain.

5 moles of oxygen react to 4 moles of NH₃

Our 9.6 moles of oxygen may react to (9.6 . 4) /5 = 7.68 moles

We only have 7.2 moles of NH₃ and we need 7.68; so there is no enough ammonia and that's our limiting reagent.

Now we determine the moles of product.

4 moles of ammonia can produce 4 moles of NO

Definetely our 7.2 moles, will produce 7.2 moles of oxide.

We convert to mass: 7.2 mol . 30 g/mol = 216 g

Answer:

its B .Eat it for energy.

Answer:

Jules

Explanation:

Answer:

Prairie dog#3

Explanation:

:)

Answer:

Because glaciers are so sensitive to temperature fluctuations accompanying climate change. so if it gets hotter then the ice glaciers will melt.

Explanation:

Answer:true

Explanation:The molecular formula indicates the exact number of atoms in the molecule. The empirical formula expresses the smallest whole number ratio of the atoms in the element.

Answer: 1). The temperature of this gas is 1032.88 K.

2). There are 21.48 moles of gas exist at a pressure of 14.5 atm, a volume of 45 liters, and a temperature of [tex]97^{o}C[/tex].

Explanation:

1). Given: No. of moles = 6 moles

Pressure = 10.6 atm

Volume = 48 L

Formula used to calculate temperature is as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 atm

T = temperature

Substitute the values into above formula as follows.

[tex]PV = nRT\\10.6 atm \times 48 L = 6 mol \times 0.0821 L atm/mol K \times T\\T = \frac{10.6 atm \times 48 L}{6 mol \times 0.0821 L atm/mol K}\\= \frac{508.8}{0.4926} K\\= 1032.88 K[/tex]

Hence, temperature of this gas is 1032.88 K.

2). Given: Pressure = 14.5 atm

Volume = 45 L

Temperature = [tex]97^{o}C = (97 + 273) K = 370 K[/tex]

Formula used to calculate number of moles is as follows.

[tex]PV = nRT\\14.5 atm \times 45 L = n \times 0.0821 L atm/mol K \times 370 K\\n = \frac{14.5 atm \times 45 L}{0.0821 L atm/mol K \times 370 K}\\= \frac{652.5}{30.377} mol\\= 21.48 mol[/tex]

Hence, there are 21.48 moles of gas exist at a pressure of 14.5 atm, a volume of 45 liters, and a temperature of [tex]97^{o}C[/tex].

Answer:

S>0 contributes to spontaneity.

Explanation:

i just took the test on a pex :)

According to the law of thermodynamics, the relationship between entropy and the spontaneity of a reaction is S > 0.

Entropy is the total amount of energy in a closed system that is present there, but there are no uses for that energy. It is the unused energy for any work.

By the second law of thermodynamics, any spontaneous process results in an increase in the universe's overall entropy. The total of the entropy produced by the spontaneous process and the change in energy brought on by the heat flow is known as the net change in entropy of the system or S.

The reaction will be spontaneous if the delta G is negative. Delta G is the Gibbs free energy. So the entropy S will be greater that the reaction.

The Gibbs free energy equation is:

△G = △H − T△S

Thus, the relation is S > 0.

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Answer:is an observation about chemical equilibria of reactions. It states that changes in the temperature, pressure, volume, or concentration of a system will result in predictable and opposing changes in the system

Explanation:

Answer:

Element Z

Explanation:

I hope this is correct and helps you!

Answer:

two or more substances that are visibly distinguishable.

Answer:

As shown previously on Natalia's experiment, oil spills will dangerously affect birds' abilities to user their feathers. When oil gets on a feather, the mass of it increases and it becomes soggy and wet. If birds try to go in water like the ocean, it will not get any better because the ocean is cold. Flying won't be easy because they have additional weight stuck to them.

Explanation:

Hope this helps you!

Answer:

O₂ is limiting reactant and 6.17g CO₂ can be produced

Explanation:

Based on the balanced reaction:

C₈H₁₈ + 25/2O₂ → 8CO₂ + 9H₂O

1 mole of C₈H₁₈ reacts with 25/2 moles O₂.

To solve this question we must convert the mass of each reactant to moles and, using the balanced reaction, we can find limiting reactant. With moles of limiting reactant we can find the moles of CO₂ and its mass as follows:

Moles C₈H₁₈ -Molar mass: 114.23g/mol-

2.28g * (1mol / 114.23g) = 0.0200 moles C₈H₁₈

Moles O₂ -Molar mass: 32g/mol-

7.00g * (1mol / 32g) = 0.219 moles O₂

For a complete reaction of 0.0200 moles C₈H₁₈ are needed:

0.0200 moles C₈H₁₈ * (25/2moles O₂ / 1mole C₈H₁₈) = 0.250 moles of O₂ are needed.

As there are just 0.219 moles, O₂ is limiting reactant.

Moles of CO₂ that can be produced:

0.219 moles O₂ * (8moles CO₂ / 25/2moles O₂) = 0.140 moles CO₂

The mass is -Molar mass CO₂: 44.01g/mol-:

0.140 moles CO₂ * (44.01g / mol) =

Answer:  Mass is 2,37 kg

Explanation: Weight G = mg, and g = 9.81 m/s² on Earth.

m = W/g = 23.2 N /  9.81 m/s²

Answer:

one

Explanation:

Answer:

The solubility of a saturated solution can be increased by increasing the temperature.

Explanation:

Temperature -- Generally, an increase in the temperature of the solution increases the solubility of a solid solute. For example, a greater amount of sugar will dissolve in warm water than in cold water. A few solid solutes, however, are less soluble in warmer solutions.

Answer:

B A B  sorry if its wrong

Explanation:

Circuits can be connected in series or parallel but the maximum voltage is obtained in series connection, thus, light bulbs shine brightest in series connection.

A parallel circuit connection is one in which the terminals of all the components in th circuit meet at two points.

The components are parallel to each other and current flows in multiple directions.

A series connection in a circuit is one in which the terminals of the component parts in a circuit are joined end to end. Current flows in one direction.

The voltage in a series connection is the sum of all the individual cells, therefore, the light bulb in series connection shines brightest.

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Answer:

 They have the same amount of energy. They are all positively charged. They are all made up of atoms.

Answer:

they have the same quantity of energy...

Answer:

4.6 mol Si

General Formulas and Concepts:

Atomic Structure

Stoichiometry

Explanation:

Step 1: Define

[Given] 2.8 × 10²⁴ atoms Si

[Solve] moles Si

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

4.64962 mol Si ≈ 4.6 mol Si

Answer:

maybe 200g

I don't know thats just a guess

HOPE ITS TURE

Answer:

Chemical bonding - a mutual adhesion of atoms in an molecule and the crystal lattice.

Explanation:

Hope you have a great day