A student performed an investigation at sea level. First she placed 400 mL of water in four different containers. Then she placed the containers on hot plates with four different temperature settings, as shown in the table.

Answer:

361.4 pm is the length of the edge of the unit cell

Explanation:

First, let's calculate the average volume each atom is taking. Start with calculating how many moles of copper we have in a cubic centimeter by looking up the atomic weight. Atomic weight copper = 63.546 Now divide the mass by the atomic weight, getting 8.94 g / 63.546 g/mol = 0.140685488 mol And multiply by Avogadro's number to get the number of atoms: 0.140685488 * 6.022140857x10^23 = 8.472278233x10^22 Now examine the face-centered cubic unit cell to see how many atoms worth of space it consumes. There is 1 atom at each of the 8 corners and each of those atoms is shared between 8 unit cells for for a space consumption of 8/8 = 1 atom. And there are 6 faces, each with an atom in the center, each of which is shared between 2 unit cells for a space consumption of 6/2 = 3 atoms. So each unit cell consumes as much space as 4 atoms. Let's divide the number of atoms in that cubic centimeter by 4 to determine the number of unit cells in that volume. 8.472278233x10^22 / 4 = 2.118069558x10^22 Now calculate the volume each unit cell occupies. 1 cm^3 / 2.118069558x10^22 = 4.721280262x10^-23 cm^3 Let's get the cube root to get the length of an edge. (4.721280262x10^-23 cm^3)^(1/3) = 3.61426x10^-08 cm Now let's convert from cm to pm. 3.61426x10^-08 cm / 100 cm/m * 1x10^12 pm/m = 361.4 pm Doing an independent search for the Crystallographic Features of Copper, I see that the Lattice Parameter for copper at at 293 K is 3.6147 x 10^-10 m which is in very close agreement with the calculated amount above. And since metals expand and contract with heat and cold, I assume the slight difference in values is due to the density figure given being determined at a temperature lower than 293 K.

The Henderson-Hasselbalch equation  can be given as

\(p^{H}\) = \(pK_{a}\) + log \(\frac{[A^{-}] }{[HA]}\)

This equation relates the \(p^{H}\) , dissociation constant and concentration of acid and its conjugate base or base and its conjugate acid.

The Henderson-Hasselbalch equation can be derived as,

Let us consider the ionization of weak  acid,

HA  + \(H_{2}O\) ⇄ \(H^{+}\) + \(A^{-}\)

The dissociation constant \(K_{a}\) can be given as

\(K_{a}\) =   \(\frac{[H^{+}][A^{-}] }{[HA]}\)

Rearranging  the equation,

\([H^{+}]\) = \(K_{a}\) ×\(\frac{[HA]}{[A^{-}] }\)

Taking log on both sides,

log\([H^{+}]\) =log{ \(K_{a}\) ×\(\frac{[HA]}{[A^{-}] }\))

log \([H^{+}]\) = log \(K_{a}\) +log \(\frac{[HA]}{[A^{-}] }\)

multiplying the whole equation on both the sides

-log \([H^{+}]\) = - log \(K_{a}\)  - log \(\frac{[HA]}{[A^{-}] }\)

we know that -log \([H^{+}]\) = \(p^{H}\) and  - log \(K_{a}\)  =p\(K_{a}\)  

then, the equation can be rewritten as

\(p^{H}\) = p\(K_{a}\) - log \(\frac{[HA]}{[A^{-}] }\)

\(p^{H}\) = p\(K_{a}\) + log\(\frac{[A^{-}] }{[HA]}\)

\([A^-}]\) =  Concentration of conjugate base

[HA] = Concentration of weak acid,

So the Henderson-Hasselbalch equation can be modified  as,

\(p^{H}\) = \(pK_{a}\) + log([Conjugate base]/ [weak acid])

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Answer:

D

Explanation:

i did it before

Using Avogrado's constant (6.022e23):

4(6.022e23) = 2.41e24

Taking into account the reaction stoichiometry and STP conditions, the volume of nitrogen monoxide gas that is created at STP when 32.2 g of solid copper reacts with excess nitric acid is 7.5677 L.

The balanced reaction is:

3 Cu(s) + 8 HNO₃(aq) → 3 Cu(NO₃)₂ (aq) + 4 H₂O(l) + 2 NO(g)

By reaction stoichiometry, the following amounts of moles of each compound participate in the reaction:

The molar mass of the compounds is:

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

The STP conditions refer to the standard temperature and pressure, which values are 0 °C and 1 atmosphere and are reference values for gases. In these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.

The following rule of three can be applied: if by reaction stoichiometry 190.62 grams of Cu form 2 moles of NO, 32.2 grams of Cu form how many moles of NO?

moles of NO= (32.2 grams of Cu× 2 moles of NO)÷ 190.62 grams of Cu

moles of NO= 0.3378 moles

Then, 0.3378 moles of NO are formed.

Now, you can apply the following rule of three: if by definition of STP conditions 1 mole of NO occupies a volume of 22.4 liters, 0.3378 moles occupies how much volume?

volume= (0.3378 moles× 22.4 L)÷ 1 mole

volume= 7.5677 L

Finally, the volume of NO created is 7.5677 L.

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On average, the total mass of ions in 4.75 liters of Mackenzie River water is 0.466 g grams.

The formula mass of an ionic compound is determined in the same manner as the formula mass of a covalent compound is determined: by adding the average atomic masses of all the atoms in the compound's formula.

Hence, the total mass is computed as follows:

(0.820 mM Ca 2⁺) X ( 2.25 L) = 1.845 mmoles at 40.0 g/mol = 73.8 mg

(0.430 mM Mg 2⁺) X ( 2.25 L) = 0.9675 mmoles at 24.3 g/mol = 23.51 mg

(0.300 mM Na⁺) X ( 2.25 L) = 0.675 mmol at 23.0 g/mol = 15.52 mg

(0.0200 mM K⁺) X ( 2.25 L) = 0.045 mmol at 39.1 = 1.75 mg

(0.250 mM Cl-) X ( 2.25 L) = 0.5625 mmol at 35.45 g/mol = 19.94 mg

(0.380 mM SO₄²-) X ( 2.25 L) = 0.855 mmol at 96.06 g/mol = 82.13 mg

(1.82 mM HCO₃ -) X ( 2.25 L) = 4.095 mmol at 61.02 g/mol = 249.87 mg

Thus, total mass = 73.8 + 23.51 + 15.52  + 1.75 + 19.94 + 82.13 + 249.87

= 466.52mg

Converted into grams  we have:
466.52/1000

= 0.46652

Hence, on average, the total mass of these ions 4.75 L \(\approx\) 0.47 grams.

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The number of liters of oxygen, O₂, required at STP to react with 11.2 liters of CH₄ to form only CO₂ and H₂O is 22.4 liters.

The number of liters of O₂ required at STP to react with 11.2 liters of CH₄ to form only CO₂ and H₂O is determined from the balanced equation of the reaction as follows:

The balanced equation of the reaction of O₂ at STP CH₄ to form only CO₂ and H₂O is given below:

CH₄ + 2 O₂ (g) ----> CO₂ (g) + 2 H₂O (g)

From the balanced equation of the reaction of O₂ at STP CH₄, 2 moles of  O₂ reacts with one mole of CH₄.

At STP, the volume of one mole of CH₄ is equal to 22.4 liters

The number of mole of CH₄ in 11.2 liters of CH₄ will be 11.2 / 22.4 = 0.5 moles

The moles of oxygen required will be 0.5 liters * 2 /1 = 1 mole of oxygen.

At STP, the volume of one mole of O₂ is equal to 22.4 liters.

Hence, 22.4 liters of oxygen are required.

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Answer:

Mole percent of Ethanol = 0.5986 * 100 = 59.86%

Explanation:

Mole percent is the percentage of the total moles that is of a particular component.

We have to covert the ethanol and water to moles. This is given by the equation;

Number of moles =  Mass / Molar mass

Ethanol;

Number of moles = 71 / 46.07  = 1.5411 mol

Water;

Number of moles = 18.6 / 18  = 1.033 mol

Total mol = 1.5411 mol + 1.033 mol =  2.5741 mol

Mole percent of Ethanol = Number of moles /(Ethanol) / Total moles   * 100

Mole percent of Ethanol =  1.5411 mol / 2.5741 mol   * 100

Mole percent of Ethanol = 0.5986 * 100 = 59.86%

The standard enthalpy change for the reaction 2A+B⇌2C+2D is  664 kJ/mol and The heat that is absorbed when 3.70 mol of A reacts is 2456.8  J

The heat changes that take place as reactants combine to generate a product are measured by the enthalpy of a reaction.

The following formula can be used to determine the enthalpy change of a reaction:

Hess's law states that

Enthalpy of reaction =  product's enthalpy - the reactant's enthalpy.

Considering the given reaction: 2A + B ⇌ 2C + 2D  

Enthalpy of reaction =  product's enthalpy - the reactant's enthalpy.

Enthalpy of reaction (ΔH°f) = (2 C + 2 D) - (2 * A + B)

Enthalpy of reaction  (ΔH°f)  = {[2(223) + 2(-523)] - [2(-245) + 2(-387)]}

Enthalpy of reaction  (ΔH°f)  = 664 kJ/mol

ΔH = q ÷ n

ΔH = molar enthalpy (heat) of solution

q = amount of energy (heat) released or absorbed

n = moles of solute

so. q = ΔH xn

q = ΔH xn

q = 664 kJ/mol x 3.70 mol

Q= 2456.8  J

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The ion having larger charge has more density .

Hence her e

Hence

\(\\ \bull\tt\dashrightarrow 3+>2+=2+=2+\)

Mendeleeve's periodic table was based on the atomic mass of each element.

The correct answer is option A: He determined the mass of atoms of each element.

The periodic table can be described as a regular arrangement of elements based on some periodic properties. The periodic table has evolved through the ages. Its patter has been changed several times before it arrived at its present form.

The  Mendeleev periodic table was based on the mass of atoms of the elements. This table was published in Russia in 1869. His table even predicted elements that were yet to be discovered.

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Answer:

1. He arrange the elements by different properties to find a pattern!

Here are the rest!

2.. atoms are indivisible

3.  He determined the amount of charge on an electron

4. Like charges repel and opposite charges attract

5.Alpha particle deflection

Hope this helps the ballers!

The speed of light in kilometers per second is 300 kps.

According to the information on light speed from the Sun to the Earth:

Known:

Distance light travels in 10 seconds from Sun to Earth = 3,000,000 km

Average distance between Earth and Sun = 150,000,000 km

Formula:

Speed = Distance / Time

Unknown:

Speed of light in kps

Substitutions:

Distance = 3,000,000 km

Time = 10 seconds

Speed = Distance / Time

Speed = 3,000,000 km / 10 seconds

Speed = 300,000 km/s

Answer:

The speed of light in kps is 300 kps (kilometers per second).

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Answer:

A fox is a carnivore, and it receives energy indirectly from plants when it eats the chicken. By consuming the chicken, the fox is indirectly receiving energy from the plants that were consumed by the chicken.

The decomposition of aspirin (acetylsalicylic acid,\(C_{9} H_{8} O_{4}\)) can occur through the hydrolysis reaction, resulting in the formation of acetic acid (\(CH_{3} COOH\)) and salicylic acid (\(C_{7} H_{6}O_{3}\)).

The decomposition of aspirin (acetylsalicylic acid, \(C_{9} H_{8} O_{4}\)) can occur through the hydrolysis reaction, resulting in the formation of acetic acid (\(CH_{3} COOH\)) and salicylic acid (\(C_{7} H_{6}O_{3}\)). To determine the moles of each product formed, we need to consider the balanced chemical equation for the reaction:

\(C_{9} H_{8} O_{4} = > C_{7} H_{6}O_{3} +CH_{3} COOH\)

From the equation, we can see that for every 1 mole of aspirin, 1 mole of salicylic acid and 1 mole of acetic acid are produced.

Therefore, the moles of salicylic acid and acetic acid formed will be equal to the number of moles of aspirin that decomposes. If we know the amount of aspirin in moles, we can directly calculate the moles of each product based on stoichiometry.

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Answer:

0.3025 moles of CO₂  are produced

Explanation:

Reaction is: Na₂CO₃ (aq) + 2 HF (aq) → H₂O (l) + CO₂ (g) + 2 NaF (aq)

It is correctly ballanced.

If the given information stays that the excess amount is on the sodium carbonate, the HF is the limiting reagent.

We see that stoichiometry is 2:1. Moles of produced CO2, will be the half, than the original amount, we have.

Firste step: We convert the mass to moles

12.1 g . 1mol / 20g = 0.605 moles of HF

2 moles of HF can produce 1 mol of CO₂

0.605 moles of HF will produce (0.605 . 1) /2 = 0.3025 moles of CO₂

The mass of the carbon dioxide is  49.72 g from the calculation done.

The phrase "mole fraction," which is often referred to as "molar fraction" or "amount fraction," is used to describe the proportions of a mixture's components. It is an intangible quantity that expresses the proportion between the moles of a given component and the total moles in the combination.

We know that;

Number of moles of ethanol = 9.2/46 g/mol

= 0.2 moles

Now;

Number of moles of water = 216.0 g/18 g/mol

= 12 moles

Mole fraction of water = Number of water/ Total number of moles

0.9 = 12/12 + 0.2 + x

0.9(12.2 + x) = 12

10.98 + 0.9x = 12

x = 1.13 moles

Now;

Moles = mass/Molar mass

1.13 = x/44

x = 49.72 g

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Answer:

municipal

Explanation:

I got state and federal wrong and after it told me it was municipal and if you where wondering I got the answers wrong on purpose to answer this one the fastest but at least I am going you the correct answer not like other people who just say a answer just because they want to but I actually got the right answer but yeah. BYEEEEEE

Answer:

municipal

Explanation:

did it and got it right

i hope you have you a great day

Answer:

Letrang A o B o C o D or Letter A or B or C or D

Answer:

See explanation.

Explanation:

Hello,

a. In this case, the change of color is evident for instance when copper reacts with nitric acid to form hydrogen and copper (II) nitrate since copper orange-like and nitric acid is colorless, but copper (II) nitrate is green (dry) or blue (hydrated).

b. In this case, when we make react hydrochloric acid and magnesium, we notice a gas giving off while the magnesium chloride remains aqueous, due to the fact that magnesium displaces hydrogen which is given off as a gas.

c. In this case, we can consider an egg since when it is edible it has a tasty smell but when it decomposes to rotten egg, hydrogen sulfide is given off due to the action of specific bacteria, causing a change in smell to a quite stinky one.

d. In this case, a reaction by which a change of state is exhibited is for instance when aqueous lead (II) nitrate reacts with aqueous potassium iodide to yield potassium nitrate which remains aqueous whereas the lead (II) iodide precipitates out as a solid due to its tiny solubility as a yellow solid.

Best regards.

The column 1 has the value of Isotope, column 2 has the value of mass in atomic mass units, and column 3 has the value of abundance and the average atomic mass of strontium is 87.47 amu.

To calculate the average atomic mass of strontium using the given information, we need to multiply the mass of each isotope by its abundance and then sum up these values. Here's the calculation:

Isotope | Mass (amu) | Abundance

^84Sr | 83.913428 | 0.56%

^86Sr | 85.909273 | 9.86%

^87Sr | 86.908902 | 7.00%

^88Sr | 87.905625 | 82.58%

To find the average atomic mass, we multiply each isotope's mass by its abundance (in decimal form) and sum up the values:

Average atomic mass = (\(Mass of ^{84Sr}\) × \(Abundance of^{84Sr}\)) + (\(Mass of ^{86Sr}\)× \(Abundance of^{86Sr}\)) + (\(Mass of ^{87Sr}\) × \(Abundance of^{87Sr}\)) + (\(Mass of ^{88Sr}\) × \(Abundance of^{88Sr}\))

Average atomic mass = (83.913428 amu × 0.0056) + (85.909273 amu × 0.0986) + (86.908902 amu × 0.0700) + (87.905625 amu × 0.8258)

Calculating this expression yields:

Average atomic mass = 0.469901638 + 8.468098826 + 6.08462314 + 72.44409075

= 87.466714354 amu

Rounding the result to two decimal places, the average atomic mass of strontium is approximately 87.47 amu.

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Answer:

A. Producing a fire gram fuel

Explanation:

None of the other actions create light. Fire gives off light and heat.

Answer:

C

Explanation:

Electromagnetic waves with higher frequencies such as X-rays and gamma rays produce harmful effects as they can damage the DNA or cells directly.

Electromagnetic radiation exhibits waves of the electromagnetic field, which travel through space and possess radiant energy. It includes microwaves, radio waves, IR, (visible) light, UV, X-rays, and gamma rays.

Electromagnetic radiation exhibits electromagnetic waves, which generally oscillate with the electric field and magnetic fields. Electromagnetic waves are generated due to periodic changes in the electric field or magnetic field.

Depending on the periodic change, the power of waves produced, and different wavelengths of the electromagnetic spectrum are produced. The effects of these radiations on chemical compounds and living organisms depend on the power of the radiation and its frequency.   Therefore, gamma rays are the most harmful radiation.

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Answer:

B. Suspension

Explanation:

A suspension is an heterogenous mixture in which the large particles settle out when not disturbed, thus ,can easily be separated by filtration.

An example is a mixture of sand and water.  When left for a while the sand particles are clearly visible at the bottom of the container if its transparent.

Answer: Yes

Explanation:

Density of a liquid depend on its volume. This is because Density is mass of liquid divided by volume.

Density is inversely proportional to volume.

As density increases, volume decreases and vice versa. The density for water is 1g/ milliliter but it changes with changes in temperature or there are impurities dissolved in it. Ice is less dense that liquid water and it's the major reason it's float because it's volume is inversely proportional to it's density.