Suppose that the NaOH sitting on the shelf had absorbed 1 g of water for every 1 g of NaOH. How would this have affected your results

Answer:

THE ENTHALPY CHANGE PER MOLE OF KOH IS 8400 Joules/ mole OF HEAT.

Explanation:

Heat = heat capacity * change in temperature

Heat capacity = 36 J/K

Temperature of the mixture before mixing = 21.5 C

Temperature of mixtire after mixing = 23.6 C

Calculate the change in temperature:

Change in temperature = 23.6 C - 21.5 C = 2.1 C

Heat = 36 * 2.1

Heat = 75.6 J of heat

In essence, 45 ml of 0.20 M of KOH produces 75.8 J of heat

The enthalpy change per mole of water:

It is important t obtain the number of moles involved in the reaction of 45 mL of 0.20 M of KOH

n = C V

n = 0.20 M * 45 *10^-3

n = 0.009 moles

Since number of moles = mass / molar mass

The mass of 45 ml of 0.20 M of KOH is then:

Molar mass = ( 39 + 16 + 1) g/mol = 56 g/mol

Mass = number of moles * molar mass

Mass = 0.009 * 56

Mass = 0.504 g

So therefore 0.504 g of KOH produces 75.6 J of heat

1 mole of KOH will produce x J of heat

1 mole of KOH = 56 g of KOH

0.504 g = 75.6 J

56 g = x J

x J = 56 * 75.6 / 0.504

x J = 8400 J / mole of KOH

Answer:

Edge length of the unit cell is 4.07x10⁻¹⁰m

Explanation:

In a face-centered cubic structure, the edge, a, could be obtained using pythagoras theorem knowing the hypotenuse of the unit cell, b, is equal to 4r:

a² + a² = b² = (4r)²

2a² = 16r²

a = √8 r

That means edge lenght is = √8 r

adius

As radius of Silver is 144pm = 144x10⁻¹²m:

a = √8 r

a = √8 ₓ 144x10⁻¹²m

a = 4.07x10⁻¹⁰m

Answer:

i. n = 5

ii. ΔE = 7.61 × [tex]10^{-46}[/tex] KJ/mole

Explanation:

1. ΔE = (1/λ) = -2.178 × [tex]10^{-18}[/tex]([tex]\frac{1}{n^{2}_{final} }[/tex] - [tex]\frac{1}{n^{2}_{initial} }[/tex])

    (1/434 × [tex]10^{-9}[/tex]) = -2.178 × [tex]10^{-18}[/tex] ([tex]\frac{n^{2}_{initial} - n^{2}_{final} }{n^{2}_{final} n^{2}_{initial} }[/tex])

⇒ 434 × [tex]10^{-9}[/tex] = (1/-2.178 × [tex]10^{-18}[/tex])[tex]\frac{n^{2}_{final} *n^{2}_{initial} }{n^{2}_{initial} - n^{2}_{final} }[/tex]

But, [tex]n_{final}[/tex] = 2

434 × [tex]10^{-9}[/tex] = (1/2.178 × [tex]10^{-18}[/tex])[tex]\frac{2^{2} n^{2}_{initial} }{n^{2}_{initial} - 2^{2} }[/tex]

434 × [tex]10^{-9}[/tex]  × 2.178 × [tex]10^{-18}[/tex] = [tex](\frac{4n^{2}_{initial} }{n^{2}_{initial} - 4 })[/tex]

⇒ [tex]n_{initial}[/tex] = 5

Therefore, the initial energy level where transition occurred is from 5.

2. ΔE = hf

     = (hc) ÷ λ

    = (6.626 × 10−34 × 3.0 × [tex]10^{8}[/tex] ) ÷ (434 × [tex]10^{-9}[/tex])

    = (1.9878 × [tex]10^{-25}[/tex]) ÷ (434 × [tex]10^{-9}[/tex])

    = 4.58 × [tex]10^{-19}[/tex] J

    = 4.58 × [tex]10^{-22}[/tex] KJ

But 1 mole = 6.02×[tex]10^{23}[/tex], then;

energy in KJ/mole = (4.58 × [tex]10^{-22}[/tex] KJ) ÷ (6.02×[tex]10^{23}[/tex])

         = 7.61 × [tex]10^{-46}[/tex] KJ/mole

The initial energy level is 5  and the energy of this transition in units of kJ/mole is 7.57 * 10^-43 kJ/mole

We must first calculate ΔE as follows;

ΔE = hc/λ

h = Plank's constant = 6.6 * 10^-34 Js

c = speed of light = 3 * 10^8 m/s

λ = wavelength = 434 * 10^-9

ΔE =  6.6 * 10^-34 * 3 * 10^8/434 * 10^-9

ΔE = 0.0456 * 10^-17 J

ΔE = [tex]ΔE = -2.178 x10^-18 (\frac{1}{n^2final} - \frac{1}{n^2initial}) \\ΔE = -2.178 x10^-18 (\frac{1}{2^2} - \frac{1}{n^2initial} )\\\\4.56 * 10^-19/2.178 x10^-18 = (\frac{1}{2^2} - \frac{1}{n^2initial})\\0.210 = (\frac{1}{2^2} - \frac{1}{n^2initial})\\\frac{1}{n^2initial} = 0.25 - 0.210\\\frac{1}{n^2final} = 0.04\\n = (\sqrt{(0.04)^-1} \\n = 5[/tex]

Energy of this transition in units of kJ/mole = 4.56 * 10^-19/ 6.02 * 10^23

= 7.57 * 10^-43 kJ/mole

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Answer:

Following are the answer to this question:

Explanation:

The answer are:

1) ketopentose

2) Triose

3) Aldose

4) Ketose

5) Glucose

6) Aldohexose

Answer:

2 Al(s) + 3 CuSO₄(aq) ⇒ 3 Cu(s) + Al₂(SO₄)₃(aq)

Explanation:

Let's consider the single displacement reaction of Al(s) with CuSO₄(aq). Copper has a higher reduction potential than aluminum, so aluminum will take the place of copper to form aluminum sulfate and metallic copper. The corresponding balanced chemical equation is:

2 Al(s) + 3 CuSO₄(aq) ⇒ 3 Cu(s) + Al₂(SO₄)₃(aq)

The chemical equation is 2 Al(s) + 3 CuSO₄(aq) ⇒ 3 Cu(s) + Al₂(SO₄)₃(aq)

here we considered the single displacement reaction of Al(s) with CuSO₄(aq). Also, Copper contained a higher reduction potential as compared to aluminum, due to this aluminum will take the place of copper to create aluminum sulfate and metallic copper. So the above should be the balance chemical equation.

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Answer:

See explanation

Explanation:

1H NMR

In the 2-chloro-pentanal we have 4 different types of hydrogens. Therefore, we will have 4 different signals. (See figure 1)

Red hydrogen

For the red hydrogens we have only 1 neighbor. So, if we follow the n+1 rule we can calculate the multiplicity of this hydrogen. In this case a doublet.

Blue hydrogens

In this case, we have 3 neighbors (one in the right, two in the left). Therefore we will have a quartet.

Purple hydrogens

For these hydrogens, we have also will have a quartet, because we have 3 neighbors (one in the right, two in the left).

Green hydrogens

In the green hydrogen,s we have 5 neighbors (2 in the right 3 in the left). Therefore a sextet would be produced.

Orange hydrogens

Finally, in these hydrogens, we have 2 neighbors. Therefore a triplet is expected.

13C NMR

For the 13C NMR, we have again 4 different kinds of carbons. Therefore we will have 4 signals. The most deshielded carbon, in this case, is the red one (see figure 2), so this carbon would be on the left side (around 190). Then the next deshield carbon is the blue one, due to the "Cl" atom placed on this carbon.

I hope it helps!

Answer: materials and design Techniques that reduce the negative environmental impact of a structure

Explanation:

Answer:

254.23 g/mol

Explanation:

Atomic mass for Osmium tetroxide would be 254.23 g/ml

Answer:254.2276

Explanation:

Answer:

the electron groups around the central nitrogen atom is trigonal planar

Explanation:

An electron group is defined as a bond (single or multiple) or/and a non-bonding electron pair around the central atom. The central nitrogen (N) atom in NO3- has three (3) electron groups (three bonds to three oxygen, O atoms).

Three electron groups around a central atom are best arranged in a trigonal planer arrangement to minimize repulsions between the bonding and/or non-bonding electrons. Therefore, the arrangement of the electron groups is trigonal planer or planer trigonal.

Answer:

[tex]\Delta _cH=-1328.3kJ/mol[/tex]

Explanation:

Helllo,

In this case, for the given chemical reaction in gaseous state:

[tex]CH_3OCH_3+3O_2\rightarrow 2CO_2+3H_2O[/tex]

We comoute the combustion enthalpy as the reaction enthalpy for one mole of fuel (dimethyl ether) considering the formation enthalpy of each given substance and whether they are reactants (subtracting) or products (adding), therefore we write:

[tex]\Delta _cH=2*\Delta _fH_{CO_2}+3*\Delta _fH_{H_2O}-\Delta _fH_{CH_3OCH_3}-3*\Delta _fH_{O_2}[/tex]

Whereas the formation enthalpies for carbon dioxide, water, dimethyl ether and oxygen are -393.5, -241.8, -184.1 and 0 kJ/mol respectively, thereby, the combustion enthalpy turns out:

[tex]\Delta _cH=2(-393.5)+3*(-241.8)-(-184.1)-3(0)\\\\\Delta _cH=-1328.3kJ/mol[/tex]

Notice that enthalpy of formation of oxygen is zero since forming an element has no chemical sense, it just exists as it has been early demonstrated.

Regards.

Answer:

See explanation

Explanation:

In this question, we have to follow the IUPAC rules. Lets analyze each compound:

a. 1-methylbutane

In this compound we have a chain of 5 carbons, so the correct name is Pentane.

b. 1,1,3-trimethylhexane

In this compound, we longest chain is made of 7 carbons, so, we have to use the name "heptane". Carbon one would be the closet one to the methyl group, so the correct name is  2,4-dimethylheptane.

c. 5-octyne

In this case, carbon 1 would be the closet one to the triplet bond. With this in mind, the correct name is oct-3-yne.

d. 2-ethyl-1-propanol

In this compound, we longest chain is made of 4 carbons, so, we have to use the name "butane". Carbon one would be the carbon with the "OH" group, so the correct name is  2-methylbutan-1-ol.

e. 2.2-dimethyl-3-butanol

In this case, carbon 1 would be the closet one to the "OH". With this in mind, the correct name is 3,3-dimethylbutan-2-ol.

See figure 1

I hope it helps!

Answer:

Sedimentary rocks

Explanation:

My explanation is that when an animal decomposes it body returns to the ground eventually being used in the rock cycle and rocks form this through the rock cycle when broken down by weathering and erosion.

Hope this helps you

Answer:

sedimentary rocks

They form from deposits that accumulate on the Earth's surface.

Answer:

The answer is "−847 J/K".

Explanation:

The given expression is:

2Al(s)+ Fe2O3(s) → Al2O3(s)+ 2Fe(s)

Δ[tex]H^{\circ}_{rxn}=[/tex] ∑(Δ[tex]H^{\circ}_{products}-H^{\circ}_{reactants}[/tex])

by the above definition Δ[tex]H^{\circ}_{element}= 0\cdot KJ \cdot Mol^{-1}[/tex] For Such a Component under standard conditions from its standard state, that also applies here. But, we start taking the overview and follow the conventions of signing:

[tex]\to (-1669)-(-822) \frac{KJ}{mol}\\\\\to (-1669+822) \frac{KJ}{mol}\\\\\to -847\frac{KJ}{mol}\\\\[/tex]

Δ[tex]H^{\circ}_{rxn}=[/tex] -847 [tex]\frac{KJ}{mol} \ mol^{-1} \texttt{ we mean \mole of Reaction as written....}\\[/tex]

Answer:

427°C .

Explanation:

Step 1:

Data obtained from the question. This include the following:

Initial temperature (T1) = 77°C

Initial pressure (P1) = P

Final pressure (P2) = 2P

Final temperature (T2) =?

Step 2:

Conversion of celsius temperature to Kelvin temperature.

This is illustrated below:

T(K) = T (°C) + 273

Initial temperature (T1) = 77°C

Initial temperature (T1) = 77°C+ 273 = 350K

Step 3:

Determination of the new temperature. The new temperature can be obtained as follow:

P1/T1 = P2/T2

P/350 = 2P/T2

Cross multiply

P x T2 = 350 x 2P

Divide both side by P

T2 = (350 x 2P ) / P

T2 = 700K

Step 4:

Conversion of Kelvin temperature to celsius temperature.

This can be obtained as follow:

T(°C) = T(K) – 273

T(K) = 700K

T(°C) = 700 – 273

T(°C) = 427°C

Therefore, the new temperature of the gas is 427°C

3.97×1023 molecules C2H6          1 mol  C2H6  

------------------------------------------ x ------------------------------------   = 0.66 mol C2H6

                                                    6.022 x 1023 molec. C2H6

Answer:

On the 2 hydrogen atoms.

Explanation:

δ+ indicates the atom has a lower electronegativity than the other atom it is bonded with. This only exist in polar covalent bonds, where the 2 atoms have different electronegativity values. When they have different electronegativity values, the one with higher electronegativity has a higher tendency to "pull" the shared electrons towards itself, they have a δ- symbol.

Back to H2O, since the electronegativity of elements increases from left to right horizontally and upwards vertically in the periodic table (except for noble gases, they are unreactive. Note that fluorine has the highest electronegativity), O atom has a higher electronegativity than hydrogen (hydrogen sits at the centre top of the table). hence, we can find δ+ on the hydrogen atoms.

Answer:

The answer is

Explanation:

Density = mass / volume

mass = density × volume

volume = 2cm³

density = 520g/cm³

mass = 2 × 520

= 1040g

Hope this helps you

Answer:

3-methylenehexane

Explanation:

In this case, we have two clues.

1) The hydrogenation reaction

2) The ozonolysis reaction

See figure 1.  

With this in mind, lets analyze each clue. In the first reaction, we know that only 1 molecule of [tex]H_2[/tex] is added to the unknown molecule. This indicates that we only have 1 double bond in the molecule. Now, the next question is where is placed the double bond?

To answer this question, we have to use the second clue. In the ozonolysis reaction, a double bond is broken and is replaced with a carbonyl group. If, formaldehyde is formed the double bond is formed with a primary carbon. The primary carbons in the structure (given in the first reaction: 3-methylhexane) are carbons 1, 6, and 7. So, the double bond can be placed between carbons:

a) 6 and 5

b) 7 and 3

c) 1 and 2

To decide which one is the position of the double bond we have to keep in mind the second product of the ozonolysis reaction a ketone. With this in mind, the carbon bonded to the primary one (deduced by the formaldehyde) it has to be a tertiary carbon. The only option that has a primary carbon bonded to tertiary carbon is b). (See figure 2)

Finally, with this in mind the structure is 3-methylenehexane. To be sure, we can check the formula for the compound, [tex]C_7H_1_4[/tex] and the reactions. (See figure 3)

I hope it helps!

Answer:

See the explanation and answer below.

Explanation:

In chemistry, the empirical formula of a chemical compound is the simplest positive integer ratio of atoms present in a compound. The formula gives the proportions of the elements present in a compound but not the actual arrangement of atoms.

[tex]\mathrm{Molecular \:Formula}\quad \quad |\quad \quad \mathrm{Empirical \:Formula}[/tex]

[tex]1.\:\:\:NH_4OH\quad | \quad H_5NO[/tex]                           (Ammonium hydroxide)

[tex]2.\:\:\:Fe(OH)_3\quad |\quad FeH_3O_3[/tex]                       (Iron(III) hydroxide)

[tex]3.\:\:\:NH_4C_2H_3O_2\quad |\quad C_2H_7NO_2[/tex]              (Ammonium acetate)

[tex]4.\:\:\:Fe(C_2H_3O_2)_3\quad |\quad C_6H_9FeO_6[/tex]            (Iron(III) Acetate)

I hate chemistry but best regards!

Answer:

O₂

Explanation:

When we create H₂O, the electrons tend to be shared by oxygen. The hydrogen bonds with the oxygen covalently, but the electrons tend to stay with the oxygen longer rather than near the hydrogens.

The approximate age of the cloth is 17190 years.

We'll begin by calculating the number of half-lives that has elapsed. This can be obtained as follow:

2ⁿ = 100 / 13

2ⁿ = 8

2ⁿ = 2³

n = 3

Finally, we shall determine the age of the cloth.

t = n × t½

t = 3  × 5730

t = 17190 years

Thus, the approximate age of the cloth is 17190 years

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Answer:

Q = 1.5 kJ

Explanation:

It is given that,

The specific heat for aluminum is 0.900 J/g°C

Mass of sample, m = 3.8 g

Initial temperature, [tex]T_i=450^{\circ} C[/tex]

Final temperature, [tex]T_f=25^{\circ} C[/tex]

We need to find the heat released. The amount of heat released is given by the formula:

[tex]Q=mc\Delta T\\\\Q=mc(T_f-T_i)\\\\Q=3.8\times 0.9\times (25-450)\\\\Q=1453.5\ J\\\\Q=1.45\ kJ[/tex]

or

[tex]Q=1.5\ kJ[/tex]

So, the correct option is (A) i.e. 1.5 kJ.

Answer:

0.109 mol/tablespoon

Explanation:

6.37 g/ 58.5 mol = 0.10888888 mol (0.109 significantly)

Answer:

A: 0.109

Explanation:

Edge 2020

Answer:

Product: propan-1-ol

Explanation:

IIn this case, we have to remember that [tex]LiAlH_4[/tex]  is a reduction agent.  So, this is a reduction reaction. The [tex]LiAlH_4[/tex] has the ability to produce hydride ions [tex]H^-[/tex]. This ion can attack the carbonyl group generating a negative charge in the oxygen. In the next step, the negative charge in the oxygen can attack a water molecule to protonate the molecule and produce propan-1-ol.

See figure 1

I hope it helps!

Answer:

here, as we have known the elements of group 3A(13) such as aluminium , boron has three valance electron and in perodic table the elements are kept with similar proterties in same place so, their valance electron is 3.

hope it helps...

The number of valence electrons are in the electron dot structures for the elements in group 3A(13) is three.

The periodic table is organized into groups (vertical columns), periods (horizontal rows), and families (groups of elements that are similar). Elements in the same group have the same number of valence electrons.

Groups are the columns of the periodic table, and periods are the rows. There are 18 groups, and there are 7 periods plus the lanthanides and actinides.

There are two different numbering systems that are commonly used to designate groups, and you should be familiar with both.

The traditional system used in the United States involves the use of the letters A and B. The first two groups are 1A and 2A, while the last six groups are 3A through 8A. The middle groups use B in their titles.

Therefore, The number of valence electrons are in the electron dot structures for the elements in group 3A(13) is three.

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Answer:

Ba(NO₃)₂(s) → Ba²⁺ + 2NO₃⁻

Explanation:

A strong electrolyte is a salt (A compound that has an anion and a cation and are neutral) that, in water, dissociates completely in its ions.

In Barium nitrate, Ba(NO₃)₂, the cation is Ba²⁺ (Alkaline earth metal), and the anion is the nitrate ion, NO₃⁻.

Thus, when Ba(NO₃)₂ (s) is dissolved in water, its transformation is:

When solid barium nitrate (Ba(NO₃)₂) dissolves in water, it undergoes a dissociation process where the compound breaks apart into its constituent ions.

Dissociation refers to the process in which a compound breaks apart into its constituent ions when dissolved in a solvent, typically water. In this process, the chemical bonds within the compound are disrupted, resulting in the separation of positive and negative ions.

The dissociation occurs due to the interaction between the solute particles and the solvent molecules, leading to the formation of hydrated ions.

The transformation can be represented as follows:

Ba(NO₃)₂(s) → Ba²⁺(aq) + 2NO₃⁻(aq)

In this process, the barium nitrate compound dissociates into barium ions (Ba²⁺) and nitrate ions (NO₃⁻) in the aqueous solution. The resulting ions are free to move and conduct electricity, indicating that barium nitrate is a strong electrolyte when dissolved in water.

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Answer:

5.42

Explanation:

Step 1: Consider the dissociation of NH₄Br

NH₄Br(aq) ⇒ NH₄⁺(aq) + Br⁻(aq)

Br⁻ is the conjugate base of HBr, a strong acid, so it doesn´t react with water. NH₄⁺ is the conjugate acid of NH₃, so it does react with water.

Step 2: Consider the acid reaction of NH₄⁺

NH₄⁺(aq) + H₂O(l) ⇄ NH₃(aq) + H₃O⁺(aq)

Step 3: calculate the acid dissociation constant for NH₄⁺

We will use the following expression.

[tex]K_a \times K_b = K_w\\K_a = \frac{K_w}{K_b} = \frac{1.00 \times 10^{-14} }{1.76 \times 10^{-5}} = 5.68 \times 10^{-10}[/tex]

Step 4: Calculate the concentration of H₃O⁺

We will use the following expression.

[tex][H_3O^{+} ]= \sqrt{K_a \times C_a } = \sqrt{5.68 \times 10^{-10} \times 0.0255 } = 3.81 \times 10^{-6}M[/tex]

Step 5: Calculate the pH

We will use the following expression.

[tex]pH = -log [H_3O^{+} ] = -log (3.81 \times 10^{-6}) = 5.42[/tex]

The pH of 0.0255 M solution should be 5.42.

Since we know that

ka * kb = kw

So,

ka = kw/kb

= 1.00*10^-14 / 1.76*10^-5

= 5.68*10^-10

Now the concentration of H3O should be

= √ka * Ca

= √5.68*10^-10 * 0.0255

= 3.81*10^-6M

Now the pH value should be

= -log(H3O+)

= -log(3.81*10^-6)

= 5.42

hence, The pH of 0.0255 M solution should be 5.42.

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Answer:

pH is a measure of the concentration of H+ ions in a solution of an acid or base. The pH plots the concentration of solutions in a range from 0–14.

Explanation:

The pH is a measure of the hydrogen ion(H^+) concentration in an acid or base. It can be obtained mathematically by the formula:

pH = —Log [H^+]

The pH scale ranges from 0 to 14

Answer:

it really is A

Explanation:

just got wrong answer because i put 16 and clearly b and c makes no sence : )

Answer:

a. boiling

Explanation:

Answer:

the mass of HBr that would react is 25.41 g of HBr

Explanation:

attached is the calculations.