In an experiment, a student places a small piece of pure Mg(s) into a beaker containing 250.mL of 6.44MHCl(aq) . A reaction occurs, as represented by the equation above.

The student collects the H2(g) produced by the reaction and measures its volume over water at 298 K after carefully equalizing the water levels inside and outside the gas-collection tube. The volume is measured to be 45.6mL . The atmospheric pressure in the lab is measured as 765 torr , and the equilibrium vapor pressure of water at 298 K is 24 torr

(ii) The number of moles of H2(g) produced in the reaction

Answer:

8 liters of 15% NaCl solution should be mixed with 2 L of a 20% NaCl solution to obtain a 16%  NaCl solution

Explanation:

The method employed here is known as alligation technique.

Alligation is a method used to calculate the proportion of any two solutions to be mixed to prepare final solution of required concentration.

Let the number of liters of the 15% NaCl solution be X

A mixture of X liters of 15% NaCl + 2 liters of 20% NaCl gives X + 2 liters of a solution whose concentration is 16%

X  * 15% + 2 * 20% = 16% * X + 2

0.15X + 2 * 0.2 = 0.16 X + 0.16 * 2

0.15X + 0.4 = 0.16X + 0.32

0.16X - 0.15X = 0.4 - 0.32

0.01X = 0.08

X = 0.08/0.01

X = 8 liters

Therefore, 8 liters of 15% NaCl solution should be mixed with 2 L of a 20% NaCl solution to obtain a 16%  NaCl solution

Answer:

Explanation:

From the given information:

[tex]2NO_2_{(g)} \to 2N_{2(g)} + O_{2(g)}[/tex]

The above reaction is a zero-order reaction.

The rate constant = 0.0067 M-s⁻¹

Suppose the volume of the flask = 4L

Initial Mol of dinitrogen monoxide = 300 mmol

The final mol of dinitrogen monoxide = 150 mmol

The molarity of dinitrogen monoxide = [tex]\dfrac{ \text{number of moles of dinitrogen monoxide }}{\text{volume of flask}}[/tex]

[tex]= \dfrac{300 \ m}{ 4 L}[/tex]

= 0.0075 mmol/L

= 0.0075 L

The final concentration  [tex]= \dfrac{150 \ m}{ 4 L}[/tex]

= 0.0375 L

By applying zero order equation

[tex]kt = [A_o] -[At][/tex]

[tex](0.0067)(t) = 0.075 - 0.0375[/tex]

[tex](0.0067)(t) = 0.0375[/tex]

[tex]\mathbf{t = 5.59 \ seconds}[/tex]

Answer:

The expression to calculate the number of moles reactants is:

n = 59.714 J / 368000 J/mole

Explanation:

Note: The question is missing some parts. The complete question is as follows:

A certain chemical reaction releases 368.kJ of heat energy per mole of reactant consumed. Suppose some moles of the reactant are put into a calorimeter (a device for measuring heat flow). It takes 4.09J of heat energy to raise the temperature of this calorimeter by 1°C. Now the reaction is run until all the reactant is gone, and the temperature of the calorimeter is found to rise by 14.6°C. How would you calculate the number of moles of reactant that were consumed?

Set the math up. But don't do any of it. Just leave your answer as a math expression.

Also, be sure your answer includes all the correct unit symbols.

Step 1: Determine the quantity of heat required to raise the temperature of the calorimeter by 14.6°C

Quantity of heat required to raise the temperature of the calorimeter by 1°C = 4.09 J

Quantity of heat required to raise the temperature of the calorimeter by 14.6°C = 4.09 * 14.6 = 59.714 J

Step 2: Express the quantity of heat released per mole of reactant in J/mole

368 kJ/mole = 368 kJ/mole * 1000 J/kJ = 368000 J/mole

Step 3: Express the moles of reactant as n and equate it to the energy absorbed by the calorimeter

Let the number of moles of reactant be n

Assuming that there is no heat lost to the surrounding, from the law of conservation of energy, Heat released = Heat absorbed

Heat released = number of moles of reactant * quantity of heat released per mole of reactant

Heat released = n * 368000 J/mole

Heat absorbed by calorimeter = 59.714 J

From the relation above, n * 368000 J/mole = 59.714 J

n = 59.714 J / 368000 J/mole

Therefore, the expression to calculate the number of moles is n = 59.714 J / 368000 J/mole

Answer:

Being an extreme blue supergiant with 59 solar masses and a surface temperature of over 42000 kelvins, Naos is actually one of the brightest stars in the Milky Way. It's almost 800 000 times as bright as the Sun, although most of that light is ultraviolet.

Explanation:

Wien's displacement law to find the approximate temperature of a star, in this case the Naos temperature would be 64000K, the real temperature is 42000K

Wien's displacement law states that the product of the maximum wavelength emitted by a black body and its temperature is constant

          λ_{max} T = 2,898 10⁻³  [ m K]

A black body is a body that absorbs all the radiation that reaches it, which is why it looks black, the cavity inside the black body must be at a fixed mask and it was there so that a thermal equilibrium is established and the radiation can be emitted by the black hole.

The stars approach a black body in the sense that their mission has a similar maximum to that of the black holes, but the temperature is an effective temperature that does not take into account the different processes within the star.

With this wavelength of the emission maximum, the temperature of the stars is calculated, in this case the star Naos is a whitish-blue star, the surface temperature found in tables is 42000K

if we use Wien's displacement law the emission should be

            λ_{max}  = 2,898 10-3 / T

            λ_{max}  = 2,898 10-3 / 42000

           λ_{max}   = 690 nm

this emission corresponds to the color orange  

For a blue emission ranging from 450 nm to 500 nm, the temperature of a black body would be

              T = 64000K to 57000 K

therefore using wien's displament law the temperature of the star Naos should be approximately 64000k, the fact that the real temperature is lower is because there are several processes with different temperatures inside the star.

In conclusion, Wien's Displacement Law can be used to find the approximate temperature of a star, in this case the Naos Temperature would be 64000K

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Answer:

Molarity[Na2S] = 0.1714

Molarity[Mgs] = 0.5811

Explanation:

Given:

0.300 mol [Na2S in 1.75 L]

31.3 g [MgS in 955 mL]

Find:

Molarity

Computation:

Molarity = Number of mole / volume in liter

Molarity[Na2S] = 0.300 / 1.75

Molarity[Na2S] = 0.1714

Molar mass of Mgs = 56.38 g/mol

Number of mole = 31.3 / 56.38

Number of mole = 0.555

Molarity[Mgs] = Number of mole / volume in liter

Molarity[Mgs] = [0.555 / 955]1000

Molarity[Mgs] = 0.5811

Answer:

Determine the moles of unknown (the solute) from the molality of the solution and the mass of solvent (in kilograms) used to make the solution. Determine the molar mass from the mass of the unknown and the number of moles of unknown.

Answer:

C. sterling hope it helps

Answer:

I will do it again soon to open the door to my house with a new year sa imo lang mam kay I have a great time to go to work for the last time

The mass of the P₂O₅ formed from 3.4 moles of O₂ gas is equal to 386.1 g.

A mole can be described as a unit for measurement of a huge number of quantities of atoms, molecules, ions, or other particles. The atomic mass can be expressed as the one mole of any element.

The number of particles present in one mole was to be equal to 6.023 × 10 ²³ which is Avogadro’s constant.

Given, the number of moles of O₂ gas = 3.4 moles

The balanced chemical reaction of phosphorous and oxygen gas can be given as:

4 P  +  5 O₂   →   2 P₂O₅

5 mol of Oxygen reacts with moles of P₂O₅ = 2 mol

3.4 mol of O₂ gas reacts with moles of P₂O₅ = (2/5) × 3.4 = 1.36 mol

The mass of the 1.36 mol of P₂O₅ = 1.36 × 283.89 = 386.1 g

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Explanation:

The major difference between low and high explosives is the rate of detonation. Low explosives detonate very slowly (less than 1,000 meters per second), whereas high explosives detonate very quickly (from 1,000 to 8,500 meters per second).

High explosives among the given list are Lead azide residues, Ammonium nitrate residues, and  Scraps of primacord. Whereas Nitrocellulose residues and, Potassium chlorate residues are low explosives.

Answer:h

Explanation:

Answer:

Acids and alkalis both contain ions. Acids contain lots of hydrogen ions, which have the symbol H+. Alkalis contain lots of hydroxide ions, symbol OH-. Water is neutral because the number of hydrogen ions is equal to the number of hydroxide ions.

Answer: The new pressure if the volume is compressed to 2.0 liters at a temperature of 450K is 2.7 atm

Explanation:

The combined gas equation is,

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

where,

[tex]P_1[/tex] = initial pressure of gas = 1.00 atm

[tex]P_2[/tex] = final pressure of gas = ?

[tex]V_1[/tex] = initial volume of gas = 3.60 L

[tex]V_2[/tex] = final volume of gas = 2.0 L

[tex]T_1[/tex] = initial temperature of gas = [tex]300K[/tex]

[tex]T_2[/tex] = final temperature of gas = [tex]450K[/tex]

Now put all the given values in the above equation, we get:

[tex]\frac{1.00\times 3.60}{300}=\frac{P_2\times 2.0}{450}[/tex]

[tex]P_2=2.7atm[/tex]

The new pressure is 2.7 atm

56.11 g/mol

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

[Compound] KOH

Step 2: Identify

[PT] Molar Mass of K - 39.10 g/mol

[PT] Molar Mass of O - 16.00 g/mol

[PT] Molar Mass of H - 1.01 g/mol

Step 3: Find

39.10 + 16.00 + 1.01 = 56.11 g/mol

Answer: drinking, bathing.

Explanation:

Answer:

The answer is actually glucose and oxygen

Answer:

The conditions are

1) Small enough

2) Electronegative atom

3) highly electronegative

4) lone pair of electrons

The correct statement therefore is

It needs to be small enough not to bump into other atoms when approaching the 1s orbital of the hydrogen, it needs to carry at least one electronegative atom, it needs to be highly electronegative enough to create a delta on the connected hydrogen, and it needs to have at least one lone pair of electrons.

Explanation:

Hydrogen bonding is a type of intermolecular bond that occurs between the partial positive charge (delta) on a hydrogen atom bonded to a small highly electronegative element (like nitrogen, oxygen or fluorine) and the free electrons on another electronegative element of another molecule.

The hydrogen atom with the partial positive charge (delta) is known as the hydrogen bond donor, while the electronegative element, carrying lone electrons is called the hydrogen bond acceptor.

Let's take a deeper look at these terms:

1) Hydrogen bond donor

Using water (H₂O) as an example, the high electronegativity of the oxygen atom covalently bonded to the hydrogen atom draws the lone electron in the 1s orbital of the hydrogen atom, creating a partial positive charge (d⁺) on the hydrogen atom. This is what happens within one water molecule

2) Hydrogen bond acceptor

When two or more molecules of water interact, the partial positive charge (d⁺) on the hydrogen atom of one molecule, is attracted to the valence or free electrons on the oxygen atom of a nearby molecule of water thus creating a dipole-dipole intermolecular bond known as a hydrogen bond.

For the hydrogen bond to be effective, the electronegative atom bonded to the hydrogen acting as the hydrogen bond donor in the first water molecule needs to be small enough so as not to disrupt the 1s orbital of the hydrogen atom. The smaller the size of the electronegative atom, the stronger the partial negative charge created on the hydrogen atom.

The valence or free pair of electrons on the electronegative (oxygen) atom of the second molecule of water (hydrogen bond acceptor) is what attracts the partial positive charge on the hydrogen atom to create the hydrogen bond

Answer:

Empirical formula

Explanation:

The empirical formula of a compound is the simplest whole number ratio of atoms of each element in the compound. It is determined using data from experiments and therefore empirical.

Answer:

The moon is not pulling the tide as hard

Explanation:

I suppose, I know it dills with the moon though

Explanation:

Normalmente, las olas se forman por el viento aunque su historia comienza muy lejos, en el Sol. ... Cuando el viento sopla sobre el mar, las partículas de aire rozan a las partículas de agua y se empiezan a formar pequeñas olas de pocos milímetros de longitud, llamadas ondas capilares.

Normally, waves are formed by the wind, although their history begins very far away, in the Sun. ... When the wind blows over the sea, the air particles brush against the water particles and small waves of few millimeters in length, called capillary waves.

Answer:

neap tide

Explanation:

There are two different types of tides, which are the spring tide and the neap tide.

Neap tides are weak tides which occur when the gravitational forces of the sun and the moon are at right angles to each other with respect to the earth. Since the sun and moon are at right angles, it causes a difference between the low and high tide.

The spring tide are strong tides which occur when the moon, sun and earth are in straight line. The spring tide occur during full moon and new moon.

Answer:

Neap Tides  

The result is a neap tide. The same effect happens during third quarter. These occur during first and last quarter moons. The gravitational pull is not as strong.

Explanation:

the first answer is correct

Answer:

84.8 mL

Explanation:

From the question given above, the following data were obtained:

Mass of CuNO₃ = 3.53 g

Molarity of CuNO₃ = 0.330 M

Volume of solution =?

Next, we shall determine the number of mole in 3.53 g of CuNO₃. This can be obtained as follow:

Mass of CuNO₃ = 3.53 g

Molar mass of CuNO₃ = 63.5 + 14 + (16×3)

= 63.5 + 14 + 48

= 125.5 g/mol

Mole of CuNO₃ =?

Mole = mass / Molar mass

Mole of CuNO₃ = 3.53 / 125.5

Mole of CuNO₃ = 0.028 moles

Next, we shall determine the volume of the solution. This can be obtained as follow:

Molarity of CuNO₃ = 0.330 M

Mole of CuNO₃ = 0.028 moles

Volume of solution =?

Molarity = mole /Volume

0.330 = 0.028 / Volume

Cross multiply

0.330 × Volume = 0.028

Divide both side by 0.330

Volume = 0.028 / 0.330

Volume = 0.0848 L

Finally, we shall convert 0.0848 L to millilitres (mL). This can be obtained as follow:

1 L = 1000 mL

Therefore,

0.0848 L = 0.0848 L × 1000 mL / 1 L

0.0848 L = 84.8 mL

Therefore, the volume of the solution is 84.8 mL.

Answer:

See explanation

Explanation:

A titration involves the addition of a titrant to an analyte solution. It is a method of volumetric analysis.

When a particular volume of titrant is added, the colour changes to signal the end point of the reaction.

The point at which the colour changes is called the equivalence point. This is the point at which the amount of titrant added is just enough to completely neutralize the analyte solution.

Hence the volume NaOH that needs to be added to the beaker containing HCl to cause a colour change is the volume of NaOH that is just enough to completely neutralize the HCl solution.

Answer:

(CH3)3C^+ + OH^-  --------> (CH3)3COH

Explanation:

This reaction has to do with SN1 reaction of alkyl halides. Here tert-butanol is formed from tert-butyl bromide.

The first step in the reaction is the formation of a carbocation. This is a unimolecular reaction. The rate of reaction depends on the concentration of the alkyl halide. This is a slow step and thus the rate determining step in the mechanism.

(CH3)3CBr -------> (CH3)3C^+ + Br^-

The second step is a fast step and it completes the reaction mechanism. It is a bimolecular reaction as follows;

(CH3)3C^+ + OH^-  --------> (CH3)3COH

1.69 g Mg₃N₂

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[RxN - Unbalanced] Mg + N₂ → Mg₃N₂

[RxN - Balanced] 3Mg + N₂ → Mg₃N₂

[Given] 1.22 g Mg

[Solve] grams Mg₃N₂

Step 2: Identify Conversions

[RxN] 3 mol Mg → Mg₃N₂

[PT] Molar Mass of Mg - 24.31 g/mol

[PT] Molar Mass of N - 14.01 g/mol

Molar Mass of Mg₃N₂ - 3(24.31) + 2(14.01) = 100.95 g/mol

Step 3: Stoich

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

1.68873 g Mg₃N₂ ≈ 1.69 g Mg₃N₂

Answer:

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.

Explanation:

I hope this helps :) Thank you. Plz mark brainliest.

Answer:

  4) 1.52 × 10^6 g

  5) 1.51 × 10^5 g

Explanation:

4. There are 121.63 g/mol of Sr(OH)₂, and there are 6.02214·10^23 formula units per mol. Then the number of grams is ...

  (7.5×10^27 formula units) × (121.63 g)/(6.02214×10^23 formula units)

  = 7.5×121.63/6.02214 × 10^4 g

  ≈ 1.52 × 10^6 g

__

5. H₂SO₄ has a molar mass of about 98.079 g, so the given quantity has a mass of about ...

  (9.30×10^26 formula units)(98.079 g)/(6.02214×10^23 formula units)

  = 9.30×98.079/6.02214 × 10^3 g

  ≈ 1.51 × 10^5 g

Answer:

4. 1.52×10^6 g

5. 1.51×10^5 g

Explanation:

hope it helps

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Answer:

the answer is b extraction

Answer: Decantation

Explanation:

Decantation is a method used to separate mixtures of immiscible liquids or soluble compounds from insoluble compounds.

The procedure follows that the solids are mixed together and water is added. The soluble solid dissolves and the insoluble solid settles at the bottom of the flask. Now the soluble solid is poured out gently leaving the insoluble solid behind using a glass rod.

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Answer:

isotopes have the SAME number of protonsbut DIFFERENT number of neutrons . to find out the neutrons you need to subtract atomic number from the mass "m-a=n"