Which example is the site of oxidation when the dry cell is operating?

solid zinc layer


cardboard separator


graphite rod


paste

Answer:

a

Explanation:

Answer:

I would put the final answer choice: "Scientists must first develop certain technologies before missions can be completed"

Explanation:

The first option is partially true, but we have ways around it.

The second option is straight-up false.

The third option doesn't make much sense, how can one work with technology that will be developed in the future and doesn't yet exist?

Therefore, the fourth option is the best.

Hope this helps

-cyber

Answer:

0.1082M of Barium Hydroxide

Explanation:

KHP reacts with Ba(OH)2 as follows:

2KHP + Ba(OH)2 → 2H2O + Ba²⁺ + 2K⁺ + 2P²⁻

Where 2 moles of KHP reacts per mole of barium hydroxide

To solve this question we must find the moles of KHP in 1.37g. With these moles and the reaction we can find the moles of Ba(OH)2 and its molarity using the volume of the solution (31.0mL = 0.0310L) as follows:

Moles KHP -Molar mass: 204.22g/mol-

1.37g * (1mol / 204.22g) = 0.006708 moles KHP

Moles Ba(OH)2:

0.006708 moles KHP * (1mol Ba(OH)2 / 2mol KHP) =

0.003354 moles Ba(OH)2

Molarity:

0.003354 moles Ba(OH)2 / 0.0310L =

Answer:

34.44 kg

Explanation:

First we convert 1.00 kg of phosphorus (P) into moles, using its molar mass:

Then we convert 0.03125 kmoles of P into kmoles of Ca₃(PO₄)₂:

Now we calculate the mass of 0.0625 kmoles of Ca₃(PO₄)₂:

Finally we calculate the required mass of the ore, using the definition of content percentage:

Answer:

1.91 atm

Explanation:

Step 1: Calculate Henry's constant (k)

A gas has a solubility (C) of 2.45 g/L at a pressure (P) of 0.750 atm. These two variables are related to each other through Henry's law.

C = k × P

K = C/P

K = (2.45 g/L)/0.750 atm = 3.27 g/L.atm

Step 2: Calculate the pressure required to produce an aqueous solution containing 6.25 g/L of this gas at constant temperature.

We have C = 6.25 g/L and k = 3.27 g/L.atm. The required pressure is:

C = k × P

P = C/k

P = (6.25 g/L)/(3.27 g/L.atm) = 1.91 atm

Answer:

number of moles of (N) = 0.794 moles

Explanation:

From the given information:

no of moles of nitrogen (N) = (unknown)???

mass of nitrogen = 13.5 g

molar mass of NH3 = 14 +( 1 × 3) = 17 g/mol

To calculate the no of moles of N, we have:

number of moles of (N) = mass of N/molar mass

number of moles of (N) = 13.5 g/17 g/mol

number of moles of (N) = 0.794 moles

Answer:

the photo is kind of blurry i cant really see it, sorry

Explanation:

We know that, at STP, one mole of a gas occupies 22.4 L of volume

we'll use the same principle to solve this problem

Converting given volume to Liters:

We know that 1 m³ = 1000 L

So, 20000 m³ = (20000)*(1000) L = 2 * 10⁷ L

Converting Liters to moles:

As mentioned above, at STP, one mole occupies 22.4 Liters

Number of moles in 2 * 10⁷ L = 2 * 10⁷ / 22.4

Number of moles = 8.9 * 10⁵ moles

Converting moles to number of particles:

We know that 1 mole contains 6.022 * 10²³ molecules

So, 8.9 * 10⁵ moles contain [(8.9 * 10⁵) * (6.022 * 10²³)] molecules

Number of molecules = 53.6 * 10²⁸ molecules

In proper scientific notation:

Number of molecules = 5.36 * 10²⁹ molecules

Answer:

See answer below

Explanation:

This is a Claisen condensation. In the picture below you have the mechanism and final product.

Hope this helps

Answer:

4.78 mol O2

Explanation:

Grams --> moles

Grams/molar mass = moles

153 g O2 / 32 g/mol O2 = 4.78125 (significant figures so round it up; the grams has 3 significant figures, so round it up) 4.78 mol O2

Answer:

the original substances in any chemical reaction. products. the resulting substances in any....chromium(III) oxide, and water. (NH4)2Cr2O7(s) → N2(g) + Cr2O3(s) + 4H2O(g).

Answer:

... x M x V. • Example: Prepare 800 mL of 2 M sodium chloride. ... solutions are indicated by w/v% and are defined as the grams of solute per ...

15 pages·906 KB

Answer:

82gS

Explanation:

2 Fe  + 3 S  →  Fe2S3

          ↓      ↑  

       mol → mol

        Fe         S

[tex]\frac{95 g Fe }{} \frac{1 mol Fe }{55.85 g Fe } \frac{3 mol S }{2 mol Fe } \frac{32.07 g S}{1 mol S} = 82 g S[/tex]

Explanation:

Facilitar el movimiento y desplazamiento de objetos pesados reduciendo el rose del objeto contra el suelo, Obtener un movimiento circular por efecto de la fuerza de un liquido, en el caso de contadores, molinos, centrales hidroeléctricas y turbinas.

Transmitir el movimiento de un eje a otro como en el caso de las lavadoras, bicicletas y neveras. Reducir drásticamente el esfuerzo necesario para elevar y mover objetos, como en casos de pozos de agua y ascensores Transformar movimientos giratorios en otros movimientos o viceversa. ,

Answer:

Ka = 1.14x10⁻⁸

Explanation:

First we calculate [H⁺] from the pH:

For a monoprotic weak acid, the molar concentration of H⁺ of a solution can be expressed as:

Where C is the molar concentration of the weak acid solution.

Answer:

12000j

mass=1500kg

velocity=4m/s

Kinetic Energy (K E) = 1/2 mv^2

=1/2*1500(4^2)

=1*750*16

=12000j

Answer:

the rate at which reactants form products is the same as the rate at which products form reactants

Explanation:

There is still  a reaction happening just that the second one happens the opposite happens and keeps it at net 0

Answer: 41.0

Explanation: When you multiply the two numbers you get 41 but you need to have the same amount of significant numbers as the number in the problem with the least significant numbers. I hope this helps

Answer:

when concentration increases, particles colide more often

The statement "When concentration increases, particles collide more often" is correct.

A constituent's abundance divided by the entire volume of a combination is known as concentration. Mass concentration, molar concentration, number concentration, and volume concentration are all examples of mathematical descriptions.

There are much more reactant particles travelling together as the concentration of reacting species increases. Because there would be more collisions, the reaction rate will be faster. The rate of a reaction increases as the concentration of reactants increases.

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Answer:

I'm not really sure but I thinks its

A:veuns

Answer:

(edit: nvm I figured it out, here is the answer)

Explanation:

Ions exists bound together in ionic formulae by electrostatic attraction then the ionic formula exists MgO.

The diagrams known as Lewis structures, also referred to as Lewis dot formulas, Lewis dot structures, electron dot structures, or Lewis electron dot structures, depict the interactions between the atoms in a molecule as well as any lone pairs of electrons that may be present.

A chemical compound comprehended as an ionic compound in chemistry exists one that contains ions bound together by the electrostatic forces named as ionic bonding. The molecule exists often neutral despite containing both positively and negatively charged ions, or cations and anions. Ions exists bound together in ionic formulae by electrostatic attraction.

Magnesium and oxygen:

Cation [tex]$=\mathrm{Mg}^{2+}$[/tex]

Anion [tex]$=\mathrm{O}^{2-}$[/tex]

Net charge = + 2 - 2 = 0

Formula = MgO

Therefore, the ionic formula exists MgO.

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Answer:

1c

2b

3a

Explanation:

Step 1: Write the general expression to calculate the freezing point depression

The freezing point depression is a colligative property, that can be calculated using the following expression.

ΔT = i × Kc × b

where,

i: van 't Hoff factor (number of ion particles per formula unit)

Kc:  cryoscopic constant (Kc for water: 1.86 °C.Kg/mol)

b: molality (moles of solute per kilogram of solvent)

All the solution have the same Kc and the same b (1 mol/1 kg = 1 m), so ΔTf variation will depend on i

Step 2: Calculate the freezing point of the Na₃PO₄ solution

Na₃PO₄ has 4 ions (3 Na⁺ and 1 PO₄³⁻), so i = 4.

ΔT = i × Kc × b = 4 × 1.86 °C.Kg/mol × 1 mol/kg = 7.44 °C

T = 0°C - 7.44 °C = -7.44 °C

Step 3: Calculate the freezing point of the CuSO₄ solution

CuSO₄ has 2 ions (1 Cu²⁺ and 1 SO₄²⁻), so i = 2.

ΔT = i × Kc × b = 2 × 1.86 °C.Kg/mol × 1 mol/kg = 3.72 °C

T = 0°C - 3.72 °C = -3.72 °C

Step 4: Calculate the freezing point of the C₆H₁₂O₆ solution

C₆H₁₂O₆ is a nonelectrolyte (it doesn't ionize), so i = 1

ΔT = i × Kc × b = 1 × 1.86 °C.Kg/mol × 1 mol/kg = 1.86 °C

T = 0°C - 3.72 °C = -1.86 °C

[tex] \longrightarrow\sf \pmb {Exothermic \: Reaction}[/tex]

[tex] \tt \green {An \: exothermic \: reaction \: is \: indicated \: by \: writing \: “+Heat” \: or \: “+Heat \: energy” \: or \: “+Energy” \: on \: the \: products \: side \: of \: an \: equation.}[/tex]

Answer: Heat is included as one of the products.

Explanation:

Answer:

When surface gravity is ore than the escape velocity gases can not escape from the planet.

Explanation:

Mercury is near Sun and the solar wind is also blowing out the atmosphere.

The gas on a gas giant escape into space, as it does  on mercury because mercury is closest to sun.

A gas giant is defined as  a giant planet  which is composed mainly of elements of hydrogen and helium. Gas giants are also called failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" was originally synonymous with "giant planet". However, in the 1990s, it became known that Uranus and Neptune are really a distinct class of giant planets, being composed mainly of heavier volatile substances.For this reason, Uranus and Neptune are now often classified in the separate category of ice giants.

Jupiter and Saturn consist mostly of  elements of hydrogen and helium, with heavier elements making up between 3 and 13 percent of their mass. They are thought to consist of an outer layer of compressed molecular hydrogen surrounding a layer of liquid metallic hydrogen, with probably a molten rocky core inside.

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When the switch is closed, electrons flow from the solid magnesium electrode, Mg(s) to solid silver electrode, Ag(s).

Electronegativity of metals refers to the ability of the atoms of metallic elements to attract electrons from the other metallic elements.

Electronegativity increases down the activity series.

Silver (Ag) will have more tendency to attract electron more than magnesium (Mg).

Thus, when the switch is closed, electrons flow from the solid magnesium electrode, Mg(s) to solid silver electrode, Ag(s).

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The question is incomplete, the complete question is;

The rate of reaction was measured during a chemical reaction. After the first 3 seconds, the rate of reaction was 1.8 x10−6 M/s. Which of the following would you expect after another 3 seconds? a

The rate would be higher, and the concentration of reactants would be lower.

b

The rate would be higher, and the concentration of reactants would be higher.

c

The rate would be lower, and the concentration of reactants would be lower.

d

The rate would be lower, and the concentration of reactants would be higher.

Answer:

The rate would be lower, and the concentration of reactants would be lower.

Explanation:

The rate of reaction refers to how quickly or slowly the reactants disappear or the products appear in a given reaction. The rate of reaction depends on the concentration of the reactants. Thus, as concentration decreases with time, the rate of reaction decreases accordingly.

Therefore, reaction rates tend to decrease with time since the concentration of  the reactants decrease with time as the reactants are being converted into products. Thus after three seconds, the rate would be lower, and the concentration of reactants would be lower. Hence the answer above.

Answer:

The rate would be lower, and the concentration of reactants would be higher.

Explanation:

I took the test and i think i got it right