9. A student needs to prepare 100 mL of a 0.50 M ammonium chloride, NH4Cl,
solution. How much solute does he need?

0.20 M NH₄, and 0.20 M HCI and  0.20 M NH₄, and 0.10 M HF are  combinations  that can be used to make a buffer. Thus option A and C are correct.

A buffer solution is an acid or a base aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa.Its pH changes very little when a small amount of strong acid or base is added to it.

Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean.

As the combination of HCl and NH₄, and NH₄ and HF   are  combinations  that can be used to make a buffer. Thus option A and C are correct.

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Answer:

Generally speaking, rocks in the southwestern U.S.A tend to be much older and more eroded than those found in the northeast. The rock outcrops and exposures in this region will likely consist of sedimentary layers that have been exposed due to erosion over time, as well as some ancient igneous intrusions such as granite or basalt. In comparison, the northeastern U.S.A tends to contain younger rocks with fewer signs of weathering and erosion; these outcrops and exposures may include a variety of metamorphic rocks such as slate or gneiss along with granites from nearby mountain ranges like the Appalachians or Adirondacks.

Answer:

Speed

Explanation:

Motion can be represented by a distance-time graph, which plots distance on the y-axis and time on the x-axis. The slope of a distance-time graph represents speed. The steeper the slope is, the faster the speed.

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EDTA (ethylenediaminetetraacetic acid) is commonly used to determine the hardness of water due to its ability to form complexes with metal ions, particularly calcium and magnesium ions.

Water hardness refers to the concentration of calcium and magnesium ions present in water. These ions can cause scaling, reduce the effectiveness of soaps, and have other negative effects. EDTA acts as a chelating agent, meaning it can bind to metal ions and form stable complexes.

In the process of determining water hardness, a known amount of EDTA solution is added to a water sample. The EDTA molecules form complexes with the calcium and magnesium ions present in the water.

The endpoint of the titration is reached when all the metal ions are complexed by the EDTA, resulting in a color change or an indicator reaching a specific endpoint.

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Answer: HOCl is considered the primary product when chlorine is added to water.

When chlorine is added to water, it reacts with water to form a mixture of hypochlorous acid (HOCl) and hydrochloric acid (HCl) as the primary products. The exact ratio of these products depends on the pH of the water. In acidic solutions, more HCl is formed, while in basic solutions, more HOCl is formed. HOCl is a powerful disinfectant and is commonly used in water treatment to kill bacteria, viruses, and other harmful microorganisms. It works by disrupting the cell membranes of these microorganisms, which causes them to die. However, HOCl can also react with organic compounds in the water to form harmful byproducts, such as trihalomethanes, which can pose a health risk. To minimize the formation of harmful byproducts, water treatment plants carefully control the amount of chlorine added to the water and adjust the pH of the water to optimize the formation of HOCl. Overall, the addition of chlorine to water is an important step in ensuring safe and clean drinking water for the public.

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Answer:

Explain: In order to balance the chemical equation, you need to make sure the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side. In order make both sides equal, you will need to multiply the number of atoms in each element until both sides are equal.

Answer:

So if you divide the kg of butter and the cake that will be your answer and then you should have a fraction so the fraction would be 0.25 over 2 because you simplified it. 0.25/2

Explanation:

Answer:

as per given balanced equation one mole Zn produces 1mole Hydrogen

when reacted with excess acid.

So 3 moles Zn will give 3moles Hydrogen

Explanation:

According to the balanced chemical equation, one mole of Zn produces one mole of hydrogen . Therefore, 3.86 moles of Zn metal will produce 3.86 moles of hydrogen gas.

Mole ratio refers to the ratio of the number of moles of one substance in a chemical reaction to the number of moles of another substance in the same reaction.

It is derived from the balanced chemical equation for the reaction, which indicates the relative amounts of each substance involved in the reaction.

Mole ratio is important in stoichiometry, which is the study of the quantitative relationships between reactants and products in a chemical reaction.

The given chemical reaction is written as follows:

Zn + 2 HCl ⇒ ZnCl₂ + H₂

According to the balanced chemical equation, one mole of Zn produces one mole of hydrogen . Therefore, 3.86 moles of Zn metal will produce 3.86 moles of hydrogen gas.

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Answer:

Option b) polyatomic ions

Explanation:

Polyatomic ions are ions consisting of two or more atoms.

From the question given above, we can see that each ions consist of more than one atom as shown below:

Ions >>>>>> Number of atom present

NH4+ >>>>> 2

CO32− >>>> 2

PO43− >>>> 2

Thus, we can say that the above ions are polyatomic ions.

Answer:

It's C.

Explanation:

Answer:

Boiling point: physical

Density: physical

Ductility: physical

Heat of combustion: chemical

Explanation:

Chemical properties can only be analyzed by putting the substance through a chemical reaction, such as combustion.

Physical properties can be analyzed without altering the substance chemically. With that in mind:

Boiling point is the physical property, density is the physical property, ductility is also a physical property but combustion of heat is a chemical property.

A physical property is the characteristic of a substance or compound that is observed without any change in the identity of the particular substance.

The physical properties of a substance is its colour, hardness, density, and melting as well as boiling points.

A physical property is a characteristic of matter that involves in physical change and physical changes are reversible and there is no production of any new substance.

The chemical change is the property of a substance due to which new substances are formed and it is non reversible change.

The chemical properties are flammability, toxicity, heat of combustion, coordination number, enthalpy of formation, and oxidation states.

Therefore, Boiling point is the physical property, density is the physical property, ductility is also a physical property but combustion of heat is a chemical property.

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Answer:

Answer:

0.03g

Explanation:

Given parameters:

Number of moles of Na = 0.00125mole

Unknown:

Mass in grams of Na = ?

Solution:

To find the mass of this substance, we simply multiply the number of moles with the given molar mass of Na.

 Mass of Na  = number of moles x molar mass

 Mass of Na  = 0.00125 x 23   = 0.03g

Answer:

water

Explanation:

because it's capable of dissolving more substances

Answer:

B. water  It can dissolve more substances

Explanation:

Increasing the pressure in the system would favor the forward reaction in the equilibrium, which is the production of Ni and CO gas.

According to Le Chatelier's principle, when a system at equilibrium is subjected to a change in pressure, it will shift to the direction that reduces the effect of the change.

In this case, increasing the pressure would cause the system to shift towards the side with fewer moles of gas, which is the side with solid Ni and CO gas.

Therefore, increasing the pressure would result in a higher rate of nickel production, as more Ni(CO)4 would be converted to Ni and CO gas. However, it is important to note that increasing the pressure beyond a certain point may not result in any significant changes in the rate of the reaction, as the equilibrium constant for this reaction may be reached at high pressures.

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Answer:

102 g Al₂O₃

Explanation:

To find the mass of Al₂O₃, you need to (1) convert grams Al to moles Al (via molar mass), then (2) convert moles Al to moles Al₂O₃ (via mole-to-mole ratio from reaction coefficients), and then (3) convert moles Al₂O₃ to grams Al₂O₃ (via molar mass). It is important to arrange the ratios in a way that allows for the cancellation of units. The final answer should have 3 sig figs to reflect the given values.

Molar Mass (Al): 26.98 g/mol

Molar Mass (Al₂O₃): 101.96 g/mol

4 Al + 3 O₂ ---> 2 Al₂O₃

54.0 g Al          1 mole             2 moles Al₂O₃         101.96 g
--------------  x  -----------------  x  -----------------------  x  ----------------  =  102 g Al₂O₃
                        26.98 g               4 moles Al            1 mole

Answer: 102 for 54.0 and 136 for 64.0

Explanation:

Answer:

Nucleus is the answer of your question

Answer:

nucleus is your awnser

Answer:

-5

Explanation:

For what I did was:

Switch the numbers

(35-33)

Do the math

Then add a negative because the smaller number is first meaning it will be a negative number

The balanced equation for the given redox reaction is:

2MnO4-(aq) + Zn(s) + 8H+(aq) → 2Mn2+(aq) + Zn2+(aq) + 4H2O(l)

The unbalanced redox reaction given is:

MnO4-(aq) + Zn(s) → Mn2+(aq) + Zn2+(aq)

In order to balance the redox reaction, we need to ensure that the number of atoms and charges on both sides of the equation are equal. Let's break down the reaction and balance it step by step.

First, let's balance the atoms other than oxygen and hydrogen. We have one manganese (Mn) atom on the left side and one on the right side, so the number of Mn atoms is already balanced. Similarly, we have one zinc (Zn) atom on each side, which is also balanced.

Next, let's balance the oxygen atoms. On the left side, we have four oxygen (O) atoms in the MnO4- ion, while on the right side, we have two oxygen atoms in the Mn2+ ion. To balance the oxygen atoms, we need to add two water (H2O) molecules on the right side.

Now, let's balance the hydrogen (H) atoms. On the left side, there are no hydrogen atoms, while on the right side, we have four hydrogen atoms in the two water molecules we added earlier. To balance the hydrogen atoms, we need to add four hydrogen ions (H+) on the left side.

Finally, let's balance the charges. On the left side, the overall charge is -1 from the MnO4- ion, while on the right side, the overall charge is +2 from the Mn2+ ion and +2 from the Zn2+ ion. To balance the charges, we need to add two electrons (e-) on the left side.

The balanced equation for the given redox reaction is:

2MnO4-(aq) + Zn(s) + 8H+(aq) → 2Mn2+(aq) + Zn2+(aq) + 4H2O(l)

In this balanced equation, both the number of atoms and charges are equal on both sides, satisfying the law of conservation of mass and charge.

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Answer:

Hello?

Explanation:

Answer:

hiiiiii camreaaaaaa. also hows youre dayy

Explanation:

hi :]

Answer:

0.756 J

Explanation:

Temperature change (delta T) = 0.855 degrees Celsius

Mass of water (m) = 0.2067 g

Specific heat capacity of water (c) = 4.28 J/g degrees C

Heat added = m * c * delta T

= (0.2067 * 4.28 * 0.855) J

= 0.756 J

The galvanic cell design involves the reduction of hydrogen ions to hydrogen gas at the cathode and the oxidation of hydrogen gas to hydrogen ions at the anode, resulting in a transfer of electrons and the overall reaction of 2H₂O + H₂ → 2H⁺ + 2OH⁻ + H₂.

The two half-reactions provided are:

1. 2H₂O → 2H⁺ + 2e⁻ (reduction half-reaction)

2. H₂ → 2H⁺ + 2e⁻ (oxidation half-reaction)

To design a galvanic cell, we need to combine these half-reactions in such a way that the reduction and oxidation reactions occur separately. This can be achieved by connecting the two half-cells with a salt bridge or a porous membrane.

In this case, the reduction half-reaction involves the reduction of water (H₂O) to hydrogen gas (H₂) by gaining two electrons (2e⁻). The oxidation half-reaction involves the oxidation of hydrogen gas (H₂) to hydronium ions (H⁺) by losing two electrons (2e⁻).

To construct the galvanic cell, we would typically represent the anode (oxidation) and cathode (reduction) compartments. The anode is where oxidation occurs, and the cathode is where reduction occurs. The half-cell notation for each half-reaction would look like this:

Anode (oxidation half-reaction): H₂ → 2H⁺ + 2e⁻

Cathode (reduction half-reaction): 2H₂O + 2e⁻ → 2H₂ + 2OH⁻

Overall, the balanced reaction of the galvanic cell would be:

2H₂O + H₂ → 2H⁺ + 2OH⁻ + H₂

This reaction represents the transfer of electrons from the anode to the cathode, with hydrogen ions (H⁺) being reduced to form hydrogen gas (H₂) at the cathode, and hydrogen gas (H₂) being oxidized to form hydrogen ions (H⁺) at the anode.

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Answer:

C4H802

Explanation:

Empirical formula is the simplest formula so you break the compound to its simplest form

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There are nine specific amino acids required in the diet daily.

The building blocks of proteins, known as amino acids, are crucial for the proper operation of cells in living things. Twenty different types of amino acids, each with a distinct chemical structure and side chain, are frequently present in proteins. Nine of these 20 amino acids are regarded as essential amino acids, which means that the body cannot produce them and that they must be received from food. Together with histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine, these amino acids are considered to be essential. Reduced immunological function, muscle atrophy, and poor growth and development are just a few health issues that can arise from inadequate intake of these critical amino acids.

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Answer:

n nnjhuig

Explanation:

bjbhvucvcg

The properties of solid NaOH that necessitate standardization of a NaOH solution are primarily its Hygroscopic nature, its tendency to react with atmospheric CO2, and its variable purity.

1. Hygroscopic nature: Solid NaOH (sodium hydroxide) has a strong affinity for water, meaning it readily absorbs moisture from the air. This can lead to changes in its mass and concentration, affecting the accuracy of a prepared NaOH solution.

2. Reaction with atmospheric CO2: Solid NaOH reacts with carbon dioxide (CO2) present in the air, forming sodium carbonate (Na2CO3). This reaction alters the composition of the NaOH, again affecting its concentration in a solution.

3. Variable purity: Commercially available NaOH often contains impurities due to the manufacturing process. These impurities can impact the effective concentration of NaOH in a solution.

To ensure accurate results in experiments, it's crucial to standardize the NaOH solution. Standardization is the process of determining the exact concentration of a solution using a primary standard, such as potassium hydrogen phthalate (KHP).

By titrating the NaOH solution with a known amount of primary standard, you can precisely calculate its concentration, accounting for any changes caused by its hygroscopic nature, reaction with atmospheric CO2, and impurities.

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To determine the stability of the given closed-loop transfer functions, we need to analyze the locations of the poles in the complex plane. If all the poles have negative real parts, the system is stable.

If any pole has a positive real part, the system is unstable. If there are poles on the imaginary axis or have zero real parts, further analysis is required.

a) Transfer function: 8Kc / (5S + 1)

The pole of this transfer function is at S = -1/5. Since the real part of the pole is negative, the system is stable.

b) Transfer function: 8Kc / (S^2 + 3S + 2)

The poles of this transfer function are at S = -1 and S = -2. Both poles have negative real parts, so the system is stable.

c) Transfer function: 8Kc / (S^3 + 6S^2 + 12S + 8 + 8Kc)

To determine the stability of this transfer function, we need to find the roots of the polynomial in the denominator. The characteristic equation is S^3 + 6S^2 + 12S + 8 + 8Kc = 0.

By analyzing the roots of the characteristic equation for different values of Kc, we can determine the stability. If all the roots have negative real parts for any value of Kc, the system is stable.

However, without a specific value for Kc provided, we cannot conclusively determine the stability of the system. The stability of the system will depend on the specific value of Kc and the locations of the roots of the characteristic equation. Further analysis is required to determine the stability.

In summary:

a) The system is stable.

b) The system is stable.

c) The stability requires further analysis as it depends on the specific value of Kc and the locations of the roots of the characteristic equation.

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Answer:

0.56 mi/hr

Explanation:

hope this helps

The third quantum number (m_l) of a 3s² electron in phosphorus is 0.

The third quantum number, denoted as m_l, represents the magnetic quantum number and describes the orientation of an orbital within a subshell. It can have integer values ranging from -l to +l, where l is the azimuthal quantum number.

In the electron configuration of phosphorus, we see that the 3s subshell is being filled. The azimuthal quantum number (l) for the 3s subshell is 0. Since the electron is in the 3s² subshell, there are two electrons present in the 3s orbital.

For the two electrons in the 3s orbital, they will have opposite spins due to the Pauli exclusion principle. However, the magnetic quantum number (m_l) for both electrons in the 3s orbital will be the same, which is 0.

Therefore, the third quantum number (m_l) of a 3s² electron in phosphorus is 0. This means that both electrons in the 3s orbital have the same orientation within the subshell.

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