Please help me with this question it’s really confusing lol.

Answer:

This atomic model has changed over time. Scientists used the model to make predictions. Sometimes the results of their experiments were a surprise and they did not fit with the existing model. Scientists changed the model so that it could explain the new evidence.

Explanation:

Answer:

ideal gas law. PV=nRT

Explanation:

pressure x volume = #moles x R (constant of 8.31) x temp

Answer:

1. the second one

2. we need to know what the letters go to like is there a picture?

3. the first one

4.the last one

5.the third one

Explanation:

Answer:

democritus

Explanation:

i looked it up

Camels lose less water through their urine and feces than many other mammals. Their kidneys concentrate water heavily, leading to salty urine. The intestines also reabsorb water from intestinal material as it is digested, so dry feces are produced.

Considering the definition of molarity, the molar concentration is 0.294 [tex]\frac{moles}{liter}[/tex].

Molarity reflects the concentration of a solution indicating the number of moles of solute that are dissolved in a given volume.

The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:

[tex]molarity=\frac{amount of moles of solute}{volume}[/tex]

Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].

In this case, you know:

Replacing in the definition of molarity:

[tex]molarity=\frac{0.250 moles}{0.850 L}[/tex]

Solving:

molarity= 0.294 [tex]\frac{moles}{liter}[/tex]

Finally, the molar concentration is 0.294 [tex]\frac{moles}{liter}[/tex].

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Buffer #1: 0.15 M HF(aq) and 0.10 M NaF(aq)   Buffer #2: 0.090 M HF(aq) and 0.060 M NaF(aq). The pH values of Buffers #1 and #2 are equal, and the buffering capacity of Buffer #1 is higher than that of Buffer #2.

A buffer is a solution that is capable of withstanding changes in pH caused by the introduction of acid or base substances. It may neutralize tiny quantities of additional acid or base, allowing the pH of the solution to remain reasonably constant.

For buffer 1;

Under Standard Conditions, Ka(acid dissociation constant) for HF = 3.5 × 10⁻⁴

pKa = -log Ka

pKa = -log (3.5 × 10⁻⁴)

pKa = 3.454

The formula for calculating the buffer value can be represented by:

[tex]\mathbf{pH = pKa + log \dfrac{([A^+])}{([HA])}}[/tex]

[tex]\mathbf{pH = 3.454 + log \Big(\dfrac{0.10}{0.15}}\Big)[/tex]

pH = 3.2779

For Buffer 2;

[tex]\mathbf{pH = 3.454 + log \Big(\dfrac{0.06}{0.09}}\Big)[/tex]

pH = 3.2779

We can see that the pH of buffer 1 is equivalent to the pH of buffer 2.

Buffer capacity measures a solution's capacity to endure pH fluctuations by either accepting or detaching H+ and OH- ions.

For Buffer 1:

The buffer capacity can be expressed by using the formula:

[tex]\mathbf{\beta = \dfrac{2.3 \ Ka [H^+] [C]}{(Ka+ [HA])^2}}[/tex]

where;

[tex]\mathbf{\beta = \dfrac{2.3 \ \times 3.5 \times 10^{-4} \times (0.15) (0.15 \times 2)}{(3.5 \times 10^{-4} + (0.15)^2 }}[/tex]

[tex]\mathbf{\beta = \dfrac{3.6225 \times 10^{-5}}{0.02260}}[/tex]

[tex]\mathbf{\beta = 0.0016}[/tex]

For Buffer 2:

[tex]\mathbf{\beta = \dfrac{2.3 \ \times 3.5 \times 10^{-4} \times (0.09) (0.09 \times 2)}{(3.5 \times 10^{-4} + (0.09)^2 }}[/tex]

[tex]\mathbf{\beta = \dfrac{1.3041 \times 10^{-5}}{0.008163}}[/tex]

[tex]\mathbf{\beta = 0.00159}[/tex]

Therefore, we can conclude that the pH values of Buffers #1 and #2 are equal, and the buffering capacity of Buffer #1 is higher than that of Buffer #2.

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Answer:

brak syna 25 punto, syn 13

Explanation:

Answer:

C) Reactants must be present in the exact molar ratios in the balanced chemical equations.

Explanation:

Answer:

BONJOUR.

CHEMICAL CHANGE ARE THOSE THAT FORM A NEW SUBSTANCE

PHYSICAL CHANGE ARE THOSE THAT DOESN'T FORM A NEW SUBSTANCE.

OPTION D IS THE ANSWER

I HOPE IT IS HELPFUL.

MERCI

Crystallization, followed by filtration to remove excess solution, followed by drying on a watch glass or in a warm oven, can yield pure dry crystals of zinc chloride.

Crystallization is defined as the formation of a solid in which the atoms or molecules are highly organized into a structure known as a crystal.

It can also be defined as a natural process that occurs when materials solidify from a liquid or precipitate from a liquid or gas.

There are basically three types of crystallization.

Filtration is defined as the process of removing solid particles from a liquid or gaseous fluid by using a filter medium that allows the fluid to pass through but retains the solid particles.

Zinc oxide that could react with hydrochloric acid to give you the desirable product because acid is a neutralizing base, the reaction of hydrochloric acid with zinc oxide to form zinc chloride and water is a neutralization reaction .

Thus, crystallization, followed by filtration to remove excess solution, followed by drying on a watch glass or in a warm oven, can yield pure dry crystals of zinc chloride.

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We have that for the Question ,it can be said that The total volume of hydrogen gas is

Vt=24.43ml

From the question we are told

Generally

With the buret divided into three

With hydrogen gas contained in the middle and value area

We have

Volume of middle

Vm=(50-31.15)

Vm=18.85ml

For Valve area

Vv=5.58ml

Therefore

The total volume of hydrogen gas is

Vt=Vm+Vv

Vt=18.85+5.58

Vt=24.43ml

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The sodium ion concentration in the solution of 17.5 mL of 0.1050 M Na₂CO₃ and 46.0 mL of 0.1250 M NaCl is 0.148 M.

To find the Na⁺ concentration in the final solution, we need to find the number of moles of the ion in the Na₂CO₃ and NaCl solutions and the volume of the final solution.  

[tex] C_{Na^{+}} = \frac{n_{t}}{V_{t}} [/tex]  (1)

Where:

[tex] n_{t} [/tex]: is the total number of moles of Na⁺

[tex] V_{t} [/tex]: is the volume of the final solution

The number of moles of Na₂CO₃ can be calculated as follows:

[tex] n_{Na_{2}CO_{3}} = C_{Na_{2}CO_{3}}*V_{Na_{2}CO_{3}} [/tex]

Where:

[tex] C_{Na_{2}CO_{3}} [/tex]: is the concentration = 0.1050 mol/L

[tex] V_{Na_{2}CO_{3}} [/tex]: is the volume = 17.5 mL = 0.0175 L

[tex] n_{Na_{2}CO_{3}} = 0.1050 mol/L*0.0175 L = 1.84 \cdot 10^{-3} \:moles [/tex]

We can find the number of moles of Na⁺ knowing that in 1 mol of Na₂CO₃ we have 2 moles of Na⁺.

[tex] n_{Na^{+}} = \frac{2 \:mol\: Na^{+}}{1\:mol \:Na_{2}CO_{3}}*mol \:Na_{2}CO_{3} = \frac{2 \:mol\: Na^{+}}{1\:mol \:Na_{2}CO_{3}}*1.84 \cdot 10^{-3} \:moles = 3.68 \cdot 10^{-3} \:moles [/tex]

The number of moles of Na⁺ in the NaCl solution is:

[tex] n_{NaCl} = C_{NaCl}*V_{NaCl} = 0.1250 mol/L*0.046 L = 5.75 \cdot 10^{-3} \:moles [/tex]

In 1 mol of NaCl we have 1 mol of Na⁺, so the number of moles of Na⁺ in the NaCl solution is 5.75x10⁻³ moles.

The total number of moles of Na⁺ in the final solution can be calculated as follows

[tex] n_{t} = n_{{Na^{+}}_{Na_{2}CO_{3}}} + n_{{Na^{+}}_{NaCl}} = 3.68 \cdot 10^{-3} \:moles + 5.75 \cdot 10^{-3} \:moles = 9.43 \cdot 10^{-3} moles [/tex]

Hence, the number of moles of Na⁺ in the final solution is 9.43x10⁻³ moles.

The volume of the final solution is given by:

[tex] V_{t} = V_{Na_{2}CO_{3}} + V_{NaCl} = 0.0175 L + 0.046 L = 0.0635 L [/tex]

The concentration of Na⁺ in the final solution is (eq 1):

[tex] C_{Na^{+}} = \frac{n_{t}}{V_{t}} = \frac{9.43 \cdot 10^{-3} moles}{0.0635 L} = 0.148 mol/L [/tex]

Therefore, the concentration of sodium ions in the final solution is 0.148 M.

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The AX3 molecular structure (one central atom with three bonded atoms) can be non-polar even with bond dipoles present  If there were no lone pairs on the central atom. Option 1 is correct.

The molecular structure or shape is a 3-D pattern showing the arrangement of atoms of a molecule.

The molecular structure of AX3 is said to be composed of a central atom connected and bounded to three atoms which are equally spaced at an angle of 120° towards one another. It has a shape of trigonal planar and its sp² hybridized that does not have any lone pair.

The polarity of a molecule or a compound has to do with the presence of lone pair in the central atom. Since AX3 has no lone pair of electrons in its central atom it is said to be non-polar.

Example of compounds that exhibit AX3 with no lone pair is: BF₃ and CO₃²⁻

Therefore, we can conclude that we've understood what is molecular structure and how to identify the molecular structures that are polar and non-polar in nature.

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The sum of coefficients for all reactants and products of given reaction is 12.

[tex]CuBr_{2} + H_{3}PO_{4}[/tex]⇨ [tex]Cu_{3} (PO_{4})_{2} + HBr[/tex]

For finding coefficients each molecules in reactant and product, first we have to balanced the given chemical equation.

The chemical equation in which number of atoms for each elements and total charges is same in both side, reactant as well as product in a reaction.

Example: Let the unbalanced chemical equation is,

[tex]CuBr_{2} + H_{3}PO_{4}[/tex]⇨ [tex]Cu_{3} (PO_{4})_{2} + HBr[/tex]

So, the balanced chemical equation become.

[tex]3CuBr_{2} + 2H_{3}PO_{4}[/tex] ⇨ [tex]Cu_{3} (PO_{4})_{2} +6 HBr[/tex]

        Reactant                   Product

The number placed prior to the each molecules is called coefficient of reactant and product.

So, the total coefficient for reactant and product are 3 + 2 + 1 + 6 = 12.

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Answer:

Step 1 of 3

Here we have to calculate the volume of the solution in mL.

(a) 2.14 g of sodium chloride from a 0.270 M solution

We can calculate the volume of a solution from its molarity. It is known that the molarity of a solution can be calculated as follows,

Molarity = 

Hence volume of solution = 

Here it has been given that,

Mass of NaCl = 2.14 g

Molarity = 0.270 M

Molecular weight of NaCl = 58.44 g/mol

In order to calculate the volume, 1st we have to find out the number of moles,

Number of moles of NaCl = 

                                     =     = 0.03662 mol of NaCl

Now the volume can be calculated as,

volume of solution = 

               =    = 0.136 L or 136 mL solution

Hence the volume of NaCl is found to be 136 mL.

Answer: The thermal energy is spread out by the surrounding air.

Explanation:

got it right on test

Answer

At the crust

Explanation:

Mantle is far away from it unless its in a ocean.

Answer:

A mountain would form on the continental crust

Explanation:

Typically, a convergent plate boundary—such as the one between the Indian Plate and the Eurasian Plate—forms towering mountain ranges, like the Himalaya, as Earth’s crust is crumpled and pushed upward.

The dew point is the temperature the air needs to be cooled to (at constant pressure) in order to achieve a relative humidity (RH) of 100%. At this point the air cannot hold more water in the gas form.

Answer:

ii cud givee uu an explanation for understandment for help if still don't understand im sowwyy thenn.

Explanation:

relative humidity is related to the partial pressure of water vapor in the air at 100% humidity the partial pressure is equal to the vapor pressure and no more water can enter the vapor phase.

Answer:

Equalize the changes in oxidation number Each Zn atom has lost two electrons, and each H atom has gained one electron. You need 2 atoms of H for every 1 atom of Zn. This gives us total changes of +2 and -2.

Explanation:

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Answer:

A state in which the concentrations of all the reactants and products remain constant with time

Explanation:

The statement which best describes chemical equilibrium is that the concentrations of all the reactants and products remain constant with time.

This is the situation in an object in which two or more forces or factors counter-influences because of them being constant.

In this scenario, the concentrations of all the reactants and products is constant which depicts the right choice.

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Answer:

a nitrogen oxide

Explanation:

i think

Answer:

Explanation:

hope this helps you!!

mark as brainliest please

Answer:

seed fibers

Explanation:

since they're harvested separately from their seed

Answer:

A physical change is reversible and the changes made are only physical (smell, physical state, volume, etc) and most importantly no new substance is formed. In a chemical change, a new substance is formed, the chemical properties are changed, and it's permanent.

Answer:

Hence, 0.455 mol of aluminum chloride could be produced from 12.0 grams of aluminum.

Explanation:

Given data:

•Mass of aluminum is 12.0 grams.

To find:

•Number of moles of aluminum chloride produced from Al.

The given reaction is as follows:

2A1+ 3Cl₂ → 2AlCl3

First, we have to find the number of moles of aluminum by the relation given below:

n = m M;

Where:

•n is the number of moles.

•m is the mass in grams.

•M is the molar mass in g/mol.

The molar mass of Al is 26.98 g/mol. Substitute the values in above equation to obtain the number of moles of aluminium as follows:

n = (12.0g)/(26.98g /mol)

= 0.445 mol

From the reaction stoichiometry, we can see that 2 moles of Al forms 2 moles of aluminium chloride (A1C13). This means, the number of moles of Al and AlCl3 is equal.

So, 0.445 mol Al will give 0.455 mol AlC13.

Answer:

YALL ITS A AND C

Explanation:

The potential energy is converted to kinetic energy as the ball rolls down the hill.

The energy that is conserved or stored in a substance or object is known as potential energy. The position, organization, or state of the object or substance determines the amount of stored energy.

Potential energy mostly comes in two forms: The potential energy of gravity and Potential elastic energy.

The energy an object has as a result of motion is known as kinetic energy. A force must be applied to an object to accelerate it. We must put in effort to apply force.

Therefore, The potential energy is converted to kinetic energy as the ball rolls down the hill.

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Explanation:

at the Anode, Oxide ions lose electrons and produce Oxygen gas

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Answer:

D. The substances are evenly distributed throughout.