what is the pH of a 1.2 M pyridine solution that has Kb =1.9 x 10^-9? The equation for the dissociation of pyridine is C3H3N(aq) + H20 (l) <-> C5H5NH+(aq) + OH-(aq). a. 4.32 b. 10.68 c. 9.68 d. 8.72

Answer:

Water plays many important roles in the body including,flushing waste from the body,regulating body temperature,transportation of nutrients and is necessary for digestion.No wonder it is considered "essential"!.Plain water is the best choice for hydrating the body.

Explanation:

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Answer:

1 grams NH3 is equal to 0.058718113128665 mole. Note that rounding errors may occur, so always check the results. Use this page to learn how to convert between grams NH3 and mole.

Explanation:

Answer:

74.3 g/mol

Explanation:

PV=nRT

P=745 mmHg: (change mmHg to atm) 745/760 = 0.9803atm

v = 0.35 L

T = 370 K

rearrange the formula above: n = \(\frac{PV}{RT}\)

plug in the info: \(\frac{(0.9803 atm)(0.35 L)}{(0.08206\frac{atm*L}{mol*K}) (370K)}\) = 0.01130 mol

then take the mass / mole = \(\frac{0.8394g}{0.01130mol}\) = 74.3 g/mol

Answer:

Explanation:

How many atoms are in a 3.5 g sample of sodium (Na)? In this example, multiply the grams of Na by the conversion factor 1 mol Na/ 22.98 g Na, with 22.98g being the molar mass of one mole of Na, which then allows cancelation of grams, leaving moles of Na.

Answer:

ONE MOLE of any element has 6.023x1023 atoms of that element. Therefore 1 mole or 22.99 grams of Na = 6.023x1023 atoms of Na.

Explanation:

Answer:

Chemical Change

Explanation:

Mixing these elements together creates a chemical change

Making of a salad dressing is a physical change  as there is no change in the chemical composition.

Physical changes are defined as changes which affect only the form of a substance but not it's chemical composition. They are used to separate mixtures in to chemical components but cannot be used to separate compounds to simpler compounds.

Physical changes are always reversible using physical means and involve a change in the physical properties.Examples of physical changes include melting,boiling , change in texture, size,color,volume and density.Magnetism, crystallization, formation of alloys are all reversible and hence physical changes.

They involve only rearrangement of atoms and are often characterized to be changes which are reversible.

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The pressure in the container is 302.42 atm

The Ideal gas law is the equation of state of a hypothetical ideal gas. It is a good approximation to the behaviour of many gases under many conditions, although it has several limitations. The ideal gas equation can be written as

                                     PV = nRT

where,

P = Pressure

V = Volume

T = Temperature

n = number of moles

Given,

Volume = 10L

Temperature = 18

Mass = 55g

Moles = mass / molar mass

= 55 / 44

= 1.25 moles

PV = nRT

P × 10 = 1.25 × 8.314 × 291

P = 302.42 atm

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Answer:

32

Explanation:

The vapour density of a gas is the number of times a given volume of gas or vapour is as heavy as the same volume of hydrogen at a particular temperature and pressure.

Vapour density = 2 × relative molecular mass of the gas or vapour

Relative molecular mass of SO2 = 32 + 2(16) = 64

Hence;

Vapour density of SO2 = 64/2

Vapour density of SO2 = 32

Answer:12

Explanation:

Answer:

Magnesium Flouride is a ionic compound and thus has a giant lattice structure. Its ions are held together in this lattice by strong electrostatic forces of attraction. A large amount of energy is needed to overcome the strong electrostatic forces of attraction between the Mg2+ ions and the F- ions to separate the ions. Hence Magnesium fluoride has a very high melting point.

Chefs measure the number of ingredients they need before preparing foods for accuracy, consistency, and balancing flavors.

Measurements ensure accuracy and consistency in recipes. Cooking is a precise process, and precise measurements of ingredients are crucial for achieving the desired taste, texture, and overall outcome of a dish. By measuring ingredients, chefs can replicate their recipes consistently, ensuring that each dish turns out as intended.

Certain ingredients, such as spices, seasonings, and acids, can greatly impact the taste of a dish. By carefully measuring these ingredients, chefs can maintain a precise balance of flavors.

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The balanced equation for the given chemical reaction is:

Cu(s) + 4 HNO3(aq) → Cu(NO3)2(aq) + 2 NO2(g) + 2 H2O(l)

In this chemical reaction, copper (Cu) reacts with nitric acid (HNO3) to produce copper nitrate, nitrogen dioxide, and water.

A balanced equation is one where the number of atoms on both sides of the equation is the same. The balanced equation shows that one copper (Cu) atom reacts with four nitric acid (HNO3) molecules, forming one copper nitrate (Cu(NO3)2) molecule, two nitrogen dioxide (NO2) molecules, and two water (H2O) molecules.

Thus, when the given equation is balanced with the lowest whole-number coefficients, the coefficients are:

Cu(s) + 4 HNO3(aq) = Cu(NO3)2(aq) + 2 NO2(g) + 2 H2O(l).

Therefore, the coefficients of the equation are Cu(s) + 4HNO3(aq) + Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l).

The solution to the problem above was provided with the correct balanced equation and a thorough explanation.

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The concentration of A after 30 seconds when the given reaction obeys the rate law rate = k[A]²[B].

We use the initial concentration of A and B and the rate constant of the reaction to find the rates at these concentrations. Using the integrated rate law for a second-order reaction, we find the concentration of A after 30 seconds to be 0.0934 M.

Given reaction obeys the rate law, rate=k[A]²[B].

Here, the initial concentration of A= 0.10 M,

initial concentration of B = 0.05 M, and

rate constant, k = 2.0 × 10⁻⁴ M⁻¹s⁻¹

We have to find the concentration of A, after 30 seconds.

To find the concentration of A, we need to know the rate at 0.10 M and 0.05 M. Therefore, we have to calculate the rates at these concentrations.

rate1 = k[A]²[B]

= (2.0 × 10⁻⁴ M⁻¹s⁻¹)(0.10 M)²(0.05 M)

= 1.0 × 10⁻⁷ M/srate2

= k[A]²[B] = (2.0 × 10⁻⁴ M⁻¹s⁻¹)(0.09 M)²(0.04 M)

= 6.48 × 10⁻⁸ M/s

Using the integrated rate law for a second-order reaction: [A] = [A]₀ - kt where [A]₀ = initial concentration of A, k = rate constant, and t = time in seconds.

We know [A]₀ = 0.10 M and k = 2.0 × 10⁻⁴ M⁻¹s⁻¹.

Substituting the values in the above equation, we get: [A] = [A]₀ - kt= 0.10 M - (2.0 × 10⁻⁴ M⁻¹s⁻¹)(30 s)≈ 0.0934 M

Therefore, the concentration of A in the vessel after 30 seconds is 0.0934 M.

This question requires us to calculate the concentration of A after 30 seconds when the given reaction obeys the rate law rate = k[A]²[B].

We are given the initial concentration of A and B and the rate constant of the reaction. To find the concentration of A after 30 seconds, we need to calculate the rates at the initial concentrations of A and B.

Using the integrated rate law for a second-order reaction, we can find the concentration of A at any given time. We substitute the given values in the formula and solve for [A]. We get the concentration of A as 0.0934 M after 30 seconds. This calculation is based on the assumption that no other reaction is important.

The concentration of A after 30 seconds when the given reaction obeys the rate law rate = k[A]²[B]. We use the initial concentration of A and B and the rate constant of the reaction to find the rates at these concentrations. Using the integrated rate law for a second-order reaction, we find the concentration of A after 30 seconds to be 0.0934 M. This calculation assumes that no other reaction is important.

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Answer:

Ring is made up off copper.

Explanation:

Given data:

Mass of ring = 89.2 g

Volume of water = 10 mL

Volume of water + ring = 20 mL

Ring is made up of = ?

Solution:

Volume of ring = (Volume of water + ring) - Volume of water

Volume of ring = 20 mL - 10 mL

Volume of ring = 10 mL

Density:

Density = mass/volume     ( 1 mL = 1 cm³)

d = 89.2 g/  10cm³

d = 8.92 g/cm³

Thus, ring is made up off copper.

The Balanced equation is:

\(NO_3^- (aq) + 2Zn (s) \rightarrow Zn^2^+ (aq) + 3NO (g)\)

A balanced equation is a chemical reaction in which the overall charge and the number of atoms for each component are exactly equal for both the products and the reactants. In simple words, the mass and charge of each side of the reaction process are equal.

One may balance equations by adhering to some basic guidelines:

1. Verify that all of the equation's formulas are accurate.

2. Focus on just one component at a time.

3. Balancing requires big number addition. A chemical formula cannot have any little numbers changed. If there has to be any balance, place the number before the substance.

4. Recheck each component and repeat step 3 if necessary.

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Answer:

Scientists were slow to let go of the current theories.

Explanation:

this is correct

All of these changes will increase the rate of a reaction.

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Answer:

Chloroplasts?

Explanation:

Answer:

Explanation:

A neutral titanium atom will have 22 electrons. Therefore, its electron configuration will be 1s2 2s2 2p6 3s2 3p6 4s2 3d2.

Answer:

d

Explanation:

the reason is you have Cu S and O

Answer:

C. Ionic-Li and S are two nonmetals

The specific heat capacity of water is 4.18 J/(g K) and the given amount of water is more than 100 grams. We need to calculate the energy absorbed by the water to reach boiling point when 5.39 × 10^5 J of heat is supplied.

The amount of water used is not provided in the question, therefore, let's first calculate the energy required to raise the temperature of 100g of water from room temperature (25°C) to its boiling point (100°C) using the formula,Q = m × c × ΔTwhere,Q = energy absorbedm = mass of waterc = specific heat capacity of waterΔT = change in temperature of water= 100 - 25 = 75°C (since the water is heated until it just begins to boil)Thus,Q = \(100 g × 4.18 J/(g K) × 75°C= 31350 J= 31.35 kJ\) of energy is required to heat 100g of water from 25°C to 100°C.

Now, let's determine the mass of water using the amount of heat energy supplied:Q =\(m × c × ΔT, where Q = 5.39 × 10^5 Jm = Q / (c × ΔT)= 5.39 × 10^5 J / (4.18 J/(g K) × 75°C)= 204.55 g\)(approx.)Therefore, more than 100 g of water is required to absorb 5.39 × 10^5 J of heat to reach its boiling point.

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Answer:

Option D, Plate Tectonics

In the rock cycle, surface events takes place at the surface of earth. Thus,

weathering and erosion are surface events, while the subsurface events he take place in the deeper section of the earth . Examples of sub surface events are plate tectonics and mountain building or anything that takes place in the inner core of earth.

Explanation:

Answer:

Option D, Plate Tectonics

In the rock cycle, surface events takes place at the surface of earth. Thus,

weathering and erosion are surface events, while the subsurface events he take place in the deeper section of the earth . Examples of sub surface events are plate tectonics and mountain building or anything that takes place in the inner core of earth.

Explanation:

Option D, Plate Tectonics

In the rock cycle, surface events takes place at the surface of earth. Thus,

weathering and erosion are surface events, while the subsurface events he take place in the deeper section of the earth . Examples of sub surface events are plate tectonics and mountain building or anything that takes place in the inner core of earth.

In the given scenario, during the passage of current through a solution of sodium chloride, 2.68×10^16 Na+ ions arrive at the negative electrode and 3.92×10^16 Cl- ions arrive at the positive electrode within a time period of 1.00 second.

The ratio of the number of Na+ ions to the number of Cl- ions is 2.68×10^16:3.92×10^16, which can be simplified to approximately 0.68:1. This indicates that for every 0.68 Na+ ions that arrive at the negative electrode, 1 Cl- ion arrives at the positive electrode.

During electrolysis, ions in the solution migrate towards the electrodes based on their charges. At the negative electrode (cathode), cations such as Na+ gain electrons and are reduced, while at the positive electrode (anode), anions like Cl- lose electrons and are oxidized. The flow of ions is driven by the applied electric field.

In this case, the ratio of Na+ ions to Cl- ions that arrive at the electrodes depends on the charge and stoichiometry of the reaction. Since the charge on each Na+ ion is +1 and on each Cl- ion is -1, the ratio of their charges is 1:1.

This implies that for every 1 Cl- ion that arrives at the positive electrode, 1 Na+ ion should arrive at the negative electrode. However, the given data shows a slightly different ratio of 0.68:1, indicating that some factors like diffusion or other side reactions may have influenced the movement of ions.

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Answer: By mass, about 96 percent of our bodies are made of four key elements: oxygen (65 percent), carbon (18.5 percent), hydrogen (9.5 percent) and nitrogen (3.3 percent). These elements do not give color to fireworks, but they are found in our body’s most abundant and important molecules, including water, proteins and DNA. The answer is B.

Explanation: I hope this helps. I got it from search.

C. Walking on wet floors shows that Friction is undesirable

Answer:

It will double in size

Explanation:

i hope its correct

Answer:

C. Oxygen

Explanation:

By looking at the periodic table.

As you look from left to right of the periods the electronegativity increases.

As well as from the bottom to the top of the groups it increases.