Please help me with this!

Answer:

I would say the second one it's the wrong

Answer:

30 2 the second power

Explanation:

Calcium hydroxide, commonly known as hydrated lime or slaked lime, is a soft white powder that is used as a primary ingredient in the chemical industry.

Its chemical formula is Ca(OH)2. When calcium oxide and water are combined, it produces.

There are two hydroxide ions (OH) in the molecule for every calcium ion (Ca2+). The substance is ionic, and both electrolytic and aqueous dissociations result in calcium and hydroxide ions.

When water is added to dry portland cement to create concrete, this reaction takes place, and the mixture warms up and releases heat. An alternative method of manufacturing entails an aqueous double displacement reaction between sodium hydroxide and calcium chloride.

Therefore, Calcium hydroxide, commonly known as hydrated lime or slaked lime, is a soft white powder that is used as a primary ingredient in the chemical industry.

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Answer:

1. It is stoichiometric.

2. O2 is the limiting reactant.

3. 9.0 g of C2H6 remain unreacted.

4. 17.6 g of CO2.

5. 85.2%.

Explanation:

Hello there!

In this case, for the given chemical reaction:

[tex]2C_2H_6+7O_2\rightarrow 4CO_2+6H_2O[/tex]

We can see that:

1. It is stoichiometric and is balanced because the reactants yields the products according to the law of conservation of mass.

2. In this part, it is possible to calculate the moles of ethane by using its molar mass:

[tex]n_{C_2H_6}=15g*\frac{1molC_2H_6}{30.08g} =0.50molC_2H_6[/tex]

And the moles of oxygen by knowing that one mole is contained in 22.4 L at STP:

[tex]n_{O_2}=\frac{1mol}{22.4L} *15.68L=0.7molO_2[/tex]

Thus, by calculating the moles of carbon dioxide product by each reactant, we can identify the limiting one:

[tex]n_{CO_2}^{by\ C_2H_6}=0.50molC_2H_6*\frac{4molCO_2}{2molC_2H_6} =1.0molCO_2\\\\n_{CO_2}^{by\ O_2}=0.70molO_2*\frac{4molCO_2}{7molO_2} =0.4molCO_2\\[/tex]

Thus, since oxygen yields the fewest moles of CO2 product, we infer it is the limiting reactant.

3. In this part, we calculate the mass of C2H6 that actually react first:

[tex]m_{C_2H_6}^{reacted}=0.4molCO_2*\frac{2molC_2H_6}{4molCO_2}*\frac{30.08gC_2H_6}{1molC_2H_6} =6.0gC_2H_6[/tex]

Thus, the leftover of ethane (C2H6) as the excess reactant is:

[tex]m_{C_2H_6 }^{leftover}=15g-6.0g=9.0g6.0C_2H_6[/tex]

4. Since 0.4 moles of carbon dioxide were produced, we use its molar mass to calculate the mass as its theoretical yield:

[tex]m_{O_2}^{theoretical}=0.4molCO_2*\frac{44gCO_2}{1molCO_2}=17.6gCO_2[/tex]

5. Finally, the percent yield is gotten by dividing the actual yield by the theoretical one:

[tex]Y=\frac{15g}{17.6}*100\%\\\\Y=85.2\%[/tex]

Best regards!

Answer:

True

Explanation:

Because yes

Answer:

true because that is a reactant or the chemical

Explanation:

Answer:

New energy level is n = 2

Explanation:

ΔE = energy released by e⁻ transition n = 7 to n(final) = - h·c/λ

h = Planck's Constant = 6.63 x 10⁻³⁴ j·s

c = speed of light in vacuum = 3 x 10⁸ m/s

λ = wavelength = 397 nm = 3.97 x 10⁻⁷ m

ΔE = - (6.63 x 10⁻³⁴j·s )(3 x 10⁸ m/s)/(3.97 x 10⁻⁷ m) = - 5.01 x 10⁻¹⁹ joule

Note: this is the transitional energy 'released' by the electron moving from n = 7 energy level to n(final) energy level. As released energy, the system should be represented by an exothermic process hence, the negative value for ΔE = - h·c/λ. The equivalent amount of energy is an absorption of electromagnetic energy (EMR) to promote the electron from n(final) to n = 7 and this would be endothermic as noted with a +h·c/λ .

The Bohr Model of the electron behavior postulates electron transitions by the release of a 'discrete' amount of EMR as emission spectra defined by the expression ...

ΔE = E(final) - E(initial) => E(final) = ΔE + E(initial)

E(n) = positional (potential) energy content of electron while in energy level n and is defined by the expression E(n) = -R(H)/n²

R(H) = Rydberg Constant = 2.18 x 10⁻¹⁸ joules

n = positional energy level (in this case) = 7

E₇ = -2.18 x 10⁻¹⁸ j / (7)² = -4.45 x 10⁻²⁰ j (potential energy of n = 7 electron)

E(final) = ΔE + E₇ = (-5.01 x 10⁻¹⁹ j)  + (-4.45 x 10⁻²⁰ j) = -4.455 x 10⁻¹⁹ j

E(final) = -R(H)/n²

=> n = SqrRt[R(H)/E(final)] = SqrRt[(-2.18 x 10⁻¹⁸ j)/(-4.455 x 10⁻¹⁹)] ≅ 2

New energy level is n = 2

Answer:

yeah they dream in weird shapes mostly I think. unless they weren't born blind then they dream normally I think

Answer:

Kind of, our dreams refer to what we see, but blind people can't see, they might have dreams what the world might look like

Answer:

solar energy drives the cycle by evaporating water from the oceans, lakes, rivers, and soil. As liquid water evaporates or transpires, it forms water vapor and clouds, where water droplets eventually gain enough mass to fall back to Earth as precipitation.

Answer:

recessive trait

Answer:

recessive

Explanation:

Color blindness is a sex-linked, recessive trait.

hope this helps and is right :)

Answer:

A)

4, 7, 4, 6

B)

12 moles

Explanation:

[tex] NH_{3}(g) + O_{2}(g) \: → NO_{2} + H_{2}O(g)[/tex]

__↑______↑

8.00 mol | 14.00 mol

________________

[tex] NH_{3}(g) + O_{2}(g) \: → NO_{2} + H_{2}O(g)[/tex]

You can turn this into a system of variables which are solvable.

To do this, create variables for the coefficients of each compound in the reaction respectively.

[tex] a(NH_{3}(g)) + b(O_{2}(g)) → \\c(NO_{2}) + d(H_{2}O(g))[/tex]

Because to be balanced, the count of atoms in each element of the compound correspond to the coefficient of the variable in that compound so that the count of the left (reactant) side is set equal to the right (product) side.

a corresponds to the coefficient of the first compound, b corresponds to the coefficient of the second compound, c corresponds to the coefficient of the third compound, and d corresponds to the coefficient of the fourth compound.

(Reactant = Product)

Reactant: 1a [N] Product: 1c.

Reactant: 3a [H] Product: 2d.

Reactant: 2b [O] Product: 2c + 1d.

Thus the system is:

1a = 1c

3a = 2d

2b = 2c + 1d.

Then just use the substitution methods to solve.

To prepare 267 mL of  0.25M NaCl, we need to take 38.29 mL of 1.75M NaCl solution and add water to it until it makes the final volume up to 267 mL.

We need to prepare the solution of 0.25 M NaCl using 1.75 M NaCl solution, we can use the dilution formula:

[tex]C_1V_1 = C_2V_2[/tex]

where [tex]C_1[/tex], [tex]V_1[/tex] is the concentration and the volume of the initial solution, [tex]C_2[/tex], [tex]V_2[/tex] is the concentration and the volume of the final solution.

We know the final concentration and the final volume that we are required to make. So we can use the above relation to find  [tex]V_1[/tex] of the solution:

[tex]V_1 = (C_2 * V_2) / C_1[/tex]

Now after substituting the values in the relation, we get:

[tex]V_1 = (0.25 M x 267 mL) / 1.75 M\\V_1 = 0.03829 L or 38.29 mL[/tex]

So to prepare 267 mL of  0.25M NaCl, we need to take 38.29 mL of 1.75M NaCl solution and add water to it until it makes the final volume up to 267 mL.

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Answer:Gravity and inertia

Answer:

A. Alpha Particle

Explanation:

I think i could be wrong

Answer: The volume of gas is 84.6 L at [tex]72.6^0C[/tex]

Explanation:

To calculate the final volume of the system, we use the equation given by Charles' Law. This law states that volume of the gas is directly proportional to the temperature of the gas at constant pressure.

Mathematically,

[tex]\frac{V_1}{T_1}=\frac{V_2}{T_2}[/tex]

where,

[tex]V_1\text{ and }T_1[/tex] are the initial volume and temperature of the gas.

[tex]V_2\text{ and }T_2[/tex] are the final volume and temperature of the gas.

We are given:

[tex]V_1=100.0L\\T_1=135^oC=(135+273)K=408K\\V_2=?\\T_2=72.0^0C=(72.0+273)K=345K[/tex]

Putting values in above equation, we get:

[tex]\frac{100.0L}{408K}=\frac{V_2}{345K}\\\\V_2=84.6L[/tex]

Thus the volume of gas is 84.6 L at [tex]72.6^0C[/tex]

Answer:

The solution is nopolar

Explanation:

Answer:

The solution does NOT conduct electricity.

Explanation:

Nonelectrolytes are usually held together by covalent bonds rather than ionic ones.

Answer:

ily

Explanation:

Answer:

c

Explanation:

cuz

Answer:

A: catalyst

Explanation:

In Chemistry, the rate of reaction of chemical elements (reactants) can be sped to produce a chemical compound or elements (products), through the addition of a catalyst that is unaffected by the reaction.

This ultimately implies that, to speed up a chemical reaction, add a catalyst that is unaffected by a reaction.

For example, an enzyme refers to a biological catalyst that is typically used to speed up (accelerate) the rate of a chemical reaction by lowering the activation energy of its reactants.

An enzyme can be defined as a biological catalyst that typically lowers the activation energy of a biological reaction. When the activation energy of a reaction is low, the rate of the reaction would be faster. Therefore, an enzyme speeds or catalyzes the rate of a reaction by lowering its activation energy.

Generally, an increase in temperature increases or speeds up the rate of a reaction while low temperature limits or reduces the rate of a reaction. The optimal temperature for enzymes in the human body is around 37 degrees celsius.

Answer:

[tex] \frac{60}{28} = \frac{15}{7} [/tex]

Answer:

Mg + 2HCl → MgCl2 + H2

Explanation:

Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2

Answer:

gravity

Explanation:

force downward due to gravity

Answer:

Gravity is the answer.

Answer:

Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

Explanation:

Answer:

B. Spring balance - a device used for measuring the weight or force of gravity acting on an object.

Explanation:

A Force is any interaction that changes the motion or position of an obkpjectbthatbit is interacting with. Whenever there is an interaction between two objects, there is a force exerted by each of the objects on one themselves.

Forces are generally divided into contact forces and non-contact over field forces.

In contact forces, the two objects physically in contact with each other. Examples of contact forces are push or pull forces, frictional forces, tensional forces, spring forces, etc.

Non-contact forces are forces in which the two objects interacting do no need to be physically in contact with one another. Examples include, gravitational forces, magnetic forces, electrical forces, etc.

Instruments used in measuring forces are known as force gauges.

From the instruments listed above:

A. A ruler is an instrument used in measuring length

B. Spring balance is a device used for measuring the weight or force of gravity acting on an object.

C. A thermometer is an instrument used in measuring temperature

D. A windbvane is an instrument used in measuring wind direction.

The scientist who wrote the universal law of gravitation was Sir Isaac Newton.

The scientist that wrote the universal law of gravitation was Isaac Newton.

The universal law of gravitation states that every object in this universe attracts every other object around it with a force, whose magnitude is directly proportional to the product of their masses and indirectly proportional to the square of the distance between them.

The universal law of gravitation was first published by the scientist Issac Newton in the year 1687.

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Answer:

Fe(s) + Cu2+(aq) ===> Fe2+(aq) + Cu(s)

Answer:

2CuFeS2+2SiO2+4O2→Cu2S+2FeSiO3+3SO2(1)

Explanation:

2CuFeS2+2SiO2+4O2→Cu2S+2FeSiO3+3SO2(1)

Answer:

c i think

Explanation:

Answer:True

Explanation:

Answer:

D - Hydroxide Ion (OH-)

Explanation:

A base provides either hydroxide ions (OH–) or other negatively charged ions that combine with hydrogen ions, reducing their concentration in the solution and thereby raising the pH. In cases where the base releases hydroxide ions, these ions bind to free hydrogen ions, generating new water molecules.

The solute wether electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water The nonelectrolyte does because it dissociates into ions.

Solute refers to substances or liquid which can readily dissolve in a solvent. It's concentration is lower to that of solvent.

Therefore, The solute wether electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water The nonelectrolyte does because it dissociates into ions

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Answer:

D: The electrolyte does because it dissociates into ions.

Explanation:

Answer:

killer T-cell find and destroy infected cells that have been turned into virus-making factories