Use the periodic table to determine the number of valence electrons in each of the following elements.
Na:
E:
V:
Ar:

Answer:

1. Ice at 0 degrees C.

2. N₂ at STP.

3. N₂ at STP.

4. Water vapor at 150 degrees C and 1 atm.

Explanation:

First, we need to remember that entropy (S) is a measure of how spread out or dispersed the energy of a system is among the different possible ways that system can contain energy. The greater the dispersal, the greater is the entropy.

When the temperature is increased, the energies associated with all types of molecular motion increase. Consequently, the entropy of a system always increases with increasing temperature.

With this in mind, we consider the pairs:

1. Since the ice at 0ºC has a greater temperature than the ice at -40 ºC, the first has the higher entropy.

2. The N₂ at STP (that is, 1 atm and 25 ºC) has higher entropy than N₂ at 0ºC and 10 atm because it has a higher temperature and less pressure, which allows a greater dispersal of energy by the molecules of the gas.

3. The N₂ at STP has a higher entropy since it has a higher temperature than N₂ at 0ºC, even though it the first has a lower volume (24,4 L vs. 50 L).

4. The water vapor at 150 ºC and 1 atm have a higher temperature and a lower pressure. This means that its molecules will have an increased molecular motion than the molecules of water vapor at a lower temperature and higher pressure. Therefore, the first has the highest entropy.

Answer: [tex]CH_3OH(l)\rightarrow CH_3OH(aq)[/tex]

Explanation:

According to the concept of “Like dissolves like”, the polar solutes dissolve in polar solvents, and non-polar solutes dissolve in non-polar solvents.

Covalent compounds which are formed by sharing of electrons between non metals, when dissolved in water, forms hydrogen bonding with water if they contain a electronegative atom along with hydrogen. Example: methanol [tex](CH_3OH)[/tex]

Ionic compounds which are made up of cations and anions, when dissolved in water, dissociate into ions. Example: [tex]NaCl[/tex]

Thus  equation which best represents methanol being dissolved in water is:

[tex]CH_3OH(l)\rightarrow CH_3OH(aq)[/tex]

Answer:

[tex]P_2=0.393atm[/tex]

Explanation:

Hello,

In this case, we can use the combined ideal gas law in order to analyze its behavior as a function of changing temperature, volume and pressure:

[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]

Thus, since we know the volume, temperature and pressure at the initial condition, we can compute the final pressure as shown below:

[tex]P_2=\frac{P_1V_1T_2}{T_1V_2} =\frac{1.00atm*225mL*(25+273)K}{(0+273)K*625mL}\\ \\P_2=0.393atm[/tex]

Regards.

Answer:

Explanation:

In the measurement of 16.50 , the measuring scale is capable of measuring upto the depth of 1 / 100th of one mL . But In the measurement of 8.0 , the measuring scale is capable of measuring upto the depth of 1 / 10th of one mL

So the former is more precise because the second scale the measurement beyond 1/ 10 th is made by guesswork which may be faulty . So the former is more precise .

Answer: his lab partner is more precise

Explanation: If the lab partner carefully measured the measurements and the other guy just determined it the lab partner's measurements should be more exact. HOPE THIS HELPS.

Explanation:

Mass = density * volume

Mass of wooden block = 2.58 * 13 = 33.54 g

Mass = density x volume  

Mass of wooden block = 2.58 x 13 = 33.54 g

Answer:

Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work (peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field.

Hope it helped u if yes mark me BRAINLIEST pzllzllzl

Tysm

Answer:

Anode

Explanation:

In the electrolysis of acidified water;

Anode half reaction;

4OH^-(aq)-----> 2H2O(l) + O2(g) + 4e

Cathode half reaction;

4H^+(aq) + 4e ----> 2H2(g)

Phenolphthalein has a pink colour in a neutral medium. A neutral medium in this electrolysis is one in which the hydroxide ion is reduced to water and oxygen and this occurs at the anode hence this is the electrode around which the solution will turn pink.

Answer:

At 336.6K, the density of the liquid is 1.212g/cm³

Explanation:

The density change in a substance with the temperature. As general (But not always applicable) rule, the density decreases with the temperature.

A formula to find density of the liquid of the problem is:

[tex]D = \frac{1.246g/cm^3}{1+8.324x10^{-5}K^{-1}*T}[/tex]

Where D is density and T is absolute temperature (In K).

If we want a density of 1.212g/cm^3:

[tex]1.212g/cm^3 = \frac{1.246g/cm^3}{1+8.324x10^{-5}K^{-1}*T}\\1.212g/cm^3+1.01x10^{-4}g/cm^3K^{-1}*T = 1.246g/cm^3\\1.01x10^{-4}g/cm^3K^{-1}*T =0.034g/cm^3\\T = 336.6K[/tex]

Answer:

A chemical compound can be described as substance composed of atoms from more than one element held together by chemical bonds in a fixed stoichiometric proportion. A compound has different physical and chemical properties from its constituent elements. Your welcome! =)

Explanation:

Answer:

If you turn the lights on and off rapidly, then the bulb will burn out faster. It's some sort of prediction

Answer:

1. If I replace the battery in my car, then my car will get better gas mileage.

2. If I eat more vegetables, then I will lose weight faster.

3. If I add fertilizer to my garden, then my plants will grow faster.

4. If I brush my teeth every day, then I will not develop cavities.

5. If I take my vitamins every day, then I will not feel tired.

6. If 50 mL of water are added to my plants each day and they grow, then adding 100 mL of water each day will make them grow even more.

Explanation:

Answer:

Organic chemistry is what people call a 'branch' of chemistry that studies the structure, properties, and reactions of organic compounds. These contain carbon in covalent bonding.

Answer: 0.4375 mols of solute

Explanation:

The problem is asking for the amount of solute. We are given the value of molarity. The molarity is 0.25M. We know that molarity is [tex]M=\frac{mols of solute}{liters of solution}[/tex]. Since we are given the liters of solution is 1.75, we can use those values to solve for mols of solute.

[tex]0.25M=\frac{x}{1.75L}[/tex]                        [multiply both sides by 1.75 L]

[tex]x=0.4375 mols[/tex]

There are 0.4375 mols of solute.

Answer:

Good precision because he is hitting the same spot 3 times but we don't know if he is accurate. SO the answer is 2

Answer:

C. Cs < K < P

Explanation:

Electronegativity is the basically the tendency of an atom to attract electrons. The pauling scale is used to quantify electronegativity, the most electronegative element; fluorine has a value of 4.0 and francium, the least electronegative element has a value of 0.7

The electronegative values of the following elements are given as;

K = 0.82

Cs =0.79

P = 2.19

Arranging in order of increasing electronegativity, we have;

Cs < K < P. The correct option is;

C. Cs < K < P

Answer:

The spin of the complex is 5.92 B.M

Explanation:

Please see the attachments below

Answer:

Zinc sulfide- more soluble in 0.10 M hydrochloric acid solution

Silver chloride- less soluble in 0.10 M hydrochloric acid solution

Lead iodide- same solubility in 0.10 M hydrochloric acid solution as in pure water

Silver hydroxide- same solubility in 0.10 M hydrochloric acid solution as in pure water

Explanation:

Solubility refers to the amount of a substance that dissolves in 1 dm^3 of solvent. Several factors influence the dissolution of solutes in a given solvent. Some substances dissolves at a low pH (in acid solutions) while other dissolve at a low pH (in basic solutions).

For Silver chloride, its solubility decreases in 0.10 M hydrochloric acid solution because of common ion effect when compared to its solubility in pure water.

Answer:

The product formed is orthonitrophenol

Explanation:

The compound orthonitrophenol is formed when ortho-bromonitrobenzene is treated with NaOH at elevated temperature.

The reaction leads to the formation of an intermediate stabilized by resonance. This intermediate can not be formed by the meta isomer because a resonance stabilized intermediate can not be formed and the product is not stabilized by intramolecular hydrogen bonding hence this reaction will not occur.

Answer:

Option 3: [tex]C_{n} H_{2n-2}[/tex]

Explanation:

Alkynes are of the homologous series of acyclic (alphatic) triple bonded carbon-carbon atoms. The could be branched or unbranched chain, but the triple bonded carbons are ether attached to hydrogen atoms or a single-bond with carbon.

Thus they carry the general formula [tex]C_{n} H_{2n-2}[/tex] across the series; where n is any integer greater than 1. The simplest forms of alkynes are acetylene molecules which have the formula [tex]C_{2} H_{2}[/tex].

I hope this explanation was resourceful and easy to understand.

Answer:

The lower the temperature, the lower the pressure inside of the sphere. If the exact values were plotted out, a linear relationship would be apparent. Extrapolating this line to the point where there would be no pressure yields absolute zero, which is about -273.15 degrees Celsius.

Answer:

Meter.

Explanation:

Hello,

In this case, The SI unit of length equal to the distance light travels in a vacuum in 1/299 792 458 of a second is the meter as the physical standard used to establish such length.

Regards.

Answer:

The product would have more acidity than Diethyl malonate

Explanation:

For this question, first, we have to start with the structure of the bromination reaction.  The bromination would add a "Br" atom in the middle carbon between the ester groups. Therefore, the molecule produced would be diethyl 2-bromomalonate and the formula of this compound fits with the reported by the question: [tex]C_7H_1_1BrO_4[/tex]

Now, if we have to analyze the acidity we have to check the most acidic hydrogen. In this case, is the "H" in the middle carbon (red hydrogen). In the Diethyl malonate, we have an inductive effect caused by the carbonyl groups on each side of the middle carbon. In the diethyl 2-bromomalonate, we have this same inductive effect plus the Br atom bonded to the same carbon. Therefore, would be easier to remove the hydrogen. So, diethyl 2-bromomalonate would ba more acidity than Diethyl malonate.

See figure 1

I hope it helps!

Answer:

Answer: II and IV

Explanation: Flammability and the ability to rust are chemical properties because they change an object. I, III, and V are physical properties because it doesn't change the object's composition. This includes weight, the change in matter (solid to liquid), or change in volume.

Hope this helps!!!

Explanation:

Answer:

Answer: II and IV

Explanation:

Explanation: Flammability and the ability to rust are chemical properties because they change an object. I, III, and V are physical properties because it doesn't change the object's composition. This includes weight, the change in matter (solid to liquid), or change in volume.

Answer:

Ka  → 1.5×10⁻⁵

Option E. None of the above

Explanation:

We propose the reaction of equlibrium

Weak ac.H +  H₂O ⇄  Weak ac⁻  +  H₃O⁺

Initially we have 0.30 moles of acid in 1 L

In equilibrium we would have:

Weak ac.H +  H₂O ⇄  Weak ac⁻  +  H₃O⁺

0.30 - x                               x               x

We have the pH, where we can obtanined the x, the [H₃O⁺] in the equilibrium.

pH = - log [H₃O⁺] → [H₃O⁺] = 10^⁻(pH)

[H₃O⁺] = 10⁻²'⁶⁷ = 2.14×10⁻³

So let's determine the concentration of the acid, in the equilibrium

0.30 - 2.14×10⁻³ = 0.29786 → [Weak ac.H]

2.14×10⁻³ →  [H₃O⁺] = Conjugate base (Weak ac.⁻)

Let's make the expression for Ka

Ka = [Weak ac.⁻] .  [H₃O⁺]  / [Weak ac.H]

Ka = x² / 0.30 - x

Ka = (2.14×10⁻³)² / 0.29786 → 1.5×10⁻⁵

Answer:

Explanation:

Weak acids do not completely dissociate in water to its distinctive ions, but instead forms conjugate bases; and ice versa with weak bases. The conjugate base has strong affinity for protons and vice versa.

I hope you found this explanation clear and easy to follow.

Answer:

The final pressure is 1556 mmHg

Explanation:

The gas laws are a set of chemical and physical laws that allow determining the behavior of gases in a closed system.

Boyle's law says that "The volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure" and is expressed mathematically as: P * V = k

 Charles's law states that the volume of gas at constant pressure is directly proportional to its temperature and is expressed mathematically as the quotient that exists between the volume and the temperature equal to a constant value:

[tex]\frac{V}{T}=k[/tex]

Gay - Lussac's law states that the pressure of gas at constant volume is directly proportional to its temperature and is expressed mathematically as the quotient between pressure and temperature equal to a constant:

[tex]\frac{P}{T}=k[/tex]

Combined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law:

[tex]\frac{P*V}{T}=k[/tex]

When you want to study two different states, an initial one and a final one of a gas, it is possible to apply:

[tex]\frac{P1*V1}{T1}=\frac{P2*V2}{T2}[/tex]

In this case:

Replacing:

[tex]\frac{570 mmHg*2270 mL}{298 K}=\frac{P2*1250 mL}{448 K}[/tex]

Solving:

[tex]P2=\frac{448K}{1250 mL} *\frac{570 mmHg*2270 mL}{298 K}[/tex]

P2= 1556 mmHg

The final pressure is 1556 mmHg