Pure gold has a density of 19.3 g/cm³. if it is made into a crown. what will be the density of the crown? how can you find out if the crown is indeed made of pure gold and nothing else?​

Answer:

pH = 9.4

Explanation:

With the given molarity of OH⁻ species we can calculate the pOH of the solution:

pOH = -log[OH⁻]

pOH = 2.6

Now we can use the pOH to calculate the pH of the solution, with the following formula:

pH = 14 - pOH

pH = 14 - 2.6

pH = 9.4

So a solution containing a OH⁻ concentration of 0.0025 M has a pH of 9.4.

Answer:

[tex]\Delta H_{comb}=2043.85kJ/mol[/tex]

Explanation:

Hello there!

In this case, according to the given chemical reaction, it possible for us to set up the expression for the calculation of the enthalpy change as shown below:

[tex]\Delta H_r=-\Delta H_{comb}=3\Delta _fH_{CO_2}+4\Delta _fH_{H_2O}-\Delta _fH_{C_3H_8}-3\Delta _fH_{O_2}[/tex]

Thus, given the values of the enthalpies of formation on the attached file, we obtain:[tex]-\Delta H_{comb}=3(-393.5kJ/mol)+4(-241.8kJ/mol)-(-103.85kJ/mol)-3(0kJ/mol)\\\\-\Delta H_{comb}=-2043.85kJ/mol\\\\\Delta H_{comb}=2043.85kJ/mol[/tex]

Best regards!

Answer:yes coefficient u mean??

Explanation:

Answer:

a gray substance and colourless liquid

Explanation:

lead oxide is reduced to lead while hydrogen is oxidized to water

Explanation:

ur question is incomplete what elements make the compound and we talk of mass not weight and what are the units kjmol ,grams ,kgs

Answer:

[tex]\boxed {\boxed {\sf A. \ 2.48 \ mol \ Na_2O}}[/tex]

Explanation:

We are asked to convert an amount in grams to moles. To do this, we use the molar mass. This is the number of grams in one mole of a substance. It is the same value numerically as the atomic mass on the Periodic Table, however the units are grams per mole, not atomic mass units.

Look up the molar masses for the individual elements.

Look back at the formula: Na₂O. Notice there is a subscript of 2 after sodium. This means there are 2 atoms of sodium in every molecule, so we have to multiply sodium's molar mass by 2 before adding oxygen's.

Set up a ratio using the molar mass.

[tex]\frac {61.9785386 \ g \ Na_2O}{1 \ mol \ Na_2O}[/tex]

Multiply by the given number of grams.

[tex]154 \ g \ Na_2O*\frac {61.9785386 \ g \ Na_2O}{1 \ mol \ Na_2O}[/tex]

Flip the ratio so the grams of sodium oxide can cancel each other out.

[tex]154 \ g \ Na_2O*\frac {1 \ mol \ Na_2O}{61.9785386 \ g \ Na_2O}[/tex]

[tex]154 *\frac {1 \ mol \ Na_2O}{61.9785386 }[/tex]

[tex]\frac {154}{61.9785386 } \ mol \ Na_2O[/tex]

[tex]2.48473106141 \ mol \ Na_2O[/tex]

The original measurement of grams given has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place.

The 4 in the thousandth place tells us to leave the 8.

[tex]2.48 \ mol \ Na_2O[/tex]

There are 2.48 moles of sodium oxide in 154 grams, so choice A is correct.

Answer:VO(ClO4)3 i'm sure this is it

Explanation:

Explanation:

its hard to explain unless we know what the question fully asks..

Answer:

45m

Explanation:

Answer:

Answer is - 2. ...........

At constant temperature, if the volume of the sample of gas decreases, the pressure increases to 4.0atm.

Hence, option1)4 atm is the correct answer.

Boyle's law simply states that "the volume of any given quantity of gas is inversely proportional to its pressure as long as temperature remains constant.

Boyle's law is expressed as;

P₁V₁ = P₂V₂

Where P₁ is Initial Pressure, V₁ is Initial volume, P₂ is Final Pressure and V₂ is Final volume.

Given the data in the question question;

We substitute our given values into the expression above to determine the new pressure.

P₁V₁ = P₂V₂

P₂ = P₁V₁ / V₂

P₂ = ( 1.0atm × 0.2L ) / 0.05L

P₂ = 0.2Latm / 0.05L

P₂ = 4atm

At constant temperature, if the volume of the sample of gas decreases, the pressure increases to 4.0atm.

Hence, option1)4 atm is the correct answer.

Learn more about Boyle's law here: brainly.com/question/1437490

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Answer:

The final pressure is 0.725 atm.

Explanation:

Gay Lussac's Law establishes the relationship between pressure and temperature of a gas when the volume is constant. This law says that when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, the pressure of the gas decreases. That is, pressure and temperature are directly proportional quantities.

Mathematically, Gay-Lussac's law states that, when a gas undergoes a constant volume transformation, the quotient of the pressure exerted by the gas temperature remains constant:

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

When analyzing an initial state 1 and a final state 2, the following is satisfied:

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

In this case:

Replacing:

[tex]\frac{0.81 atm}{306 K} =\frac{P2}{274 K}[/tex]

Solving:

[tex]P2=274 K*\frac{0.81 atm}{306 K}[/tex]

P2= 0.725 atm

The final pressure is 0.725 atm.

Answer:

genotype are the organism's hereditary information for example DNA

phenotype are the organism's physical characteristics for example your eyes or hair

or how your nose looks

Answer:

i think its magma ajani i looked it up... and chelsey said u had corona so if its true hope u get better bro

Explanation:

Answer:

The mitochondria is the organelle found in plant and animal cells and is involved in making cellular energy from respiration.

Explanation:

Answer:

answer po Yan hope it help

Answer:

[tex]=1.76gCa[/tex]

Explanation:

Hello there!

In this case, according to the given atoms of calcium, it is possible to calculate the mass of this element by considering that the definition of mole is in terms of atoms and also the atomic mass of calcium:

[tex]1molCa=6.022x10^{23}atoms Ca=40.08gCa[/tex]

In such a way, by considering the following setup, we can obtain:

[tex]=2.65x10^{22}atomsCa*\frac{1molCa}{6.022x10^{23}atoms} *\frac{40.08gCa}{1molCa}\\\\=1.76gCa[/tex]

Best regards!

Answer:

46.41%

Explanation:

Find the total r.m.m of AL(CLO3)3 put it equals to 100%.....The take 106.5,the total r.m.m of Cl and find the missing which is the percentage by cross multiplication

Answer:

Limting reactant: NaOH

Excess reactant: Al₂(SO₃)₃ by 104.9 grams.

315 g of Na₂SO₃ are produced in the reaction

67.4 % is the percent yield.

Explanation:

Balaced equation is:

Al₂(SO₃)₃ + 6NaOH → 3Na₂SO₃ + 2Al(OH)₃

We convert the mass of each reactant to moles, to identify the limiting reactant:

389.4 g . 1mol/ 342.15g = 1.14 moles of sulfite

200 g . 1mol / 40g = 5 moles

1 mol of aluminum sulfite react to 6 moles of NaOH, according to stoichiometry.

If we have 1.14 moles of sulfite, we need (1.14 . 6)/1 = 6.82 moles

We only have 5 mol of NaOH, so this is the limiting reactant.

Then the aluminum sulfite is the excess.

6 moles of NaOH react to 1 mol of sulfite

Then, 5 moles of NaOH may react to (5 . 1)/6 = 0.83 moles.

1.14 mol - 0.83 mol = 0.31 moles remains after the reaction goes complete.

We convert to mass: 0.31 mol . 342.15g/mol = 104.9 g

Then, we work with the limiting reactant. Stoichiometry is 6:3 (2)

6 moles of NaOH can produce 3 moles of sodium sulfite

Then 5 moles will produce (5 . 3)/6 = 2.5 moles

We convert moles to mass: 2.5 mol . 126 g/mol = 315 g.

Percent yield = (Yield produced/Thoeretical yield) . 100

Percent yield = (212.4g /315g) . 100 = 67.4  %

Answer:

The rate of reaction is doubled

Explanation:

The reaction between 1-iodopropane and sodium hydroxide is an SN2 reaction. This reaction takes place by a concerted mechanism and the hydroxide ion is the nucleophile.

In an SN reaction, the reaction is second order because the rate of reaction depends both on the concentration of the alkylhalide and that of the nucleophile. Hence, when the concentration of 1-iodopropane (the alkyl halide) is held constant and the concentration of hydroxide ion (the nucleophile) is doubled, the rate of reaction is doubled since;

Rate =k [1-iodopropane] [OH^-]

Answer:

C meteoroid

Explanation:

Meteoroids are the only ones of the four that are under a kilometer in size.

Heat energy will be released by solid A which will then be absorbed by liquid B.

These little particles vibrate back and forth or run into each other constantly. All matter contains a type of energy known as heat (or thermal) energy, which is produced by the movement of particles.

Particle energy increases with temperature. It is possible for some of this energy to be transferred to cooler particles. For instance, in the gas state, when a fast-moving particle strikes a slower-moving particle, some of the energy from the collision is transferred to the slower-moving particle, increasing its speed.

A region of high energy will gradually spread throughout the material as a result of billions of moving particles colliding with one another until thermal equilibrium is established.

Therefore, heat energy will be released by solid A which will then be absorbed by liquid B.

Read more about heat energy, here

https://brainly.com/question/20038450

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Answer:

See explanation

Explanation:

According to Bronsted-Lowry, an acid is a proton donor while a base is a proton acceptor.

Hence, if we consider the reaction above, we will notice that for each base there is a conjugate acid and for each acid there is a conjugate base.

For the acid HNO3, its conjugate base is NO3^- while for the acid H3O^+, its conjugate base is H2O.

Answer:

Hello There!!

Explanation:

I think the answer is possibly C. It identified the charge on a single electron.

hope this helps,have a great day!!

~Pinky~

[tex]\huge{\textbf{\textsf{{\color{navy}{An}}{\purple{sw}}{\pink{er}} {\color{pink}{:}}}}}[/tex]

C. It identified the charge on a single electron.

Explanation:

(I only know this thing vaguely lol)

1.) It's the study of the chemistry that is happening here on earth that is not bounded by a laboratory.

2.) The early gas clouds compressed and formed a star we now call the sun and the massive gravitational pull of this star grabbed nearby debris and the debris formed and compressed into the planets and moons that we know today.

Answer:

C₂H₅N₂

Explanation:

In the combustion analysis, all NO comes from the nitrogen of the sample, that means:

Moles NO = Moles N in the sample

In the same way:

Moles CO2 = Moles C in the sample

Moles H2O = 1/2 moles H in the sample

To solve this problem we must convert the mass of each gas to moles in order to find the moles of each atom. The empirical formula is the simplest whole number ratio of atoms presents in the molecule:

Moles NO = N -Molar mass: 30g/mol

0.4646g * (1mol / 30g) = 0.01549 moles N

Moles CO2 = C -Molar mass: 44.01g/mol-

0.6859g * (1mol / 44.01g) = 0.01559 moles C

Moles H2O = 1/2moles H -Molar mass: 18.02g/mol-

0.6973g * (1mol / 18.02g) = 0.03870 moles H

The ratio of atoms is -Dividing in the low number of moles = moles N-:

C = 0.01559 / 0.01549 = 1

N = 0.01549 / 0.01549 = 1

H = 0.03870 / 0.01549 = 2.5

Twice this ratio of atoms -Because empirical formula must be given only with whole numbers:

C = 2

N = 2

H = 5

The empirical formula is:

Answer:

: kinetic energy is the energy transformation that occurs in a hot balloon.

Explanation:

Hot air balloons use a propane burner that converts chemical energy to thermal energy. The hot air is less dense than than the colder air and it lifts the balloon