Which statement defines the enthalpy of solution?
the total number of particles in a solution
the phase change from a solid to a liquid
o the difference in characteristics between reactants and products
the change in energy when one substance dissolves in another

Answer:

Acidic solution used to clean a crucible

Explanation:

This liquid dissolves alcoholic solvents such as crucible, that is why it was selected as the ideal for cleaning.

Although it would be ideal to know in detail which chemical compound is the one you want to clean so that the cleaning technique has better effectiveness.

WASTE CONTAINER refers to the solvent used to rinse chemicals out of a beaker, and it also refers to the acid solution used to clean a crucible. Water used to rinse the detergent out of a flask refer to the SINK.

In conclusion, WASTE CONTAINER refers to the solvent used to rinse chemicals out of a beaker, and it also refers to the acid solution used to clean a crucible. Water used to rinse the detergent out of a flask refer to the SINK.

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The correct name of this isotope : Oxygen - 16

Given

Isotope : ₈¹⁶O

Required

The correct name

Solution

The elements in nature have several types of isotopes  

Isotopes are elements that have the same Atomic Number (Proton)  

Atomic mass is the average atomic mass of all its isotopes  

In the following element notation,

[tex]\large {{{A} \atop {Z}} \right X}[/tex]

X = symbol of elemental atom

A = mass number

Z = atomic number

The isotope name is usually followed by its mass number, so the symbol above can be expressed as oxygen - 16

Answer:

Nucleus 3 i believe

Answer:

oxidizer: one used to support the combustion of a rocket propellant

word: a single distinct meaningful element of speech or writing

Explanation:

Answer:

Bohr placed the electrons in distinct energy levels.  Rutherford described the atom as consisting of a tiny positive mass surrounded by a cloud of negative electrons. Bohr thought that electrons orbited the nucleus in quantized orbits. Also, rutherfords was just a hypothesis while Bhor took the time to make his an experiment

Answer:

Explanation:

From the given information:

The accuracy depends on the internal diameter of the cylinder. The cylinder with the least internal diameter is obviously more precise.

Let's assume 1% is the error of measurement.

Then, to measure 70 mL from 10 mL cylinder

The error = [tex]10 \times \dfrac{1}{100} \times 7[/tex]

= 0.7 mL

However; for a 100 mL cylinder, the error = 1 mL

Now,

The total volume for 10 mL = (70 + 0.7) = 70.7 mL

The total volume for 100 mL = (70 + 1 ) = 71 mL

Suppose the density (d) is same for both

Then;

the mass of 10 mL = ( d × 70.7) g

the mass pf 100 mL = (d × 71) g

Thus, the mass of 100 mL is greater than that of 10 mL.

Answer: Gravity will pull two objects together.

Explanation: It’s newton’s 1 and kinda his 2 law.

Answer:

Electron (e-)

Explanation:

An electron is just one of the fundamental particles

Answer:heyyyy

Explanation:

Answer:

1 x 10⁻¹¹moldm⁻³

Explanation:

Given parameters:

pH of the solution  = 11

Unknown:

[H] = ?

Solution:

The hydrogen ion concentration is unknown.

From:

                      PH  = - log[H⁺]  

       So;

                     11 = -log[H⁺]

               [H⁺] = 1 x 10⁻¹¹moldm⁻³

Answer:

The property P measured, was a chemical property of X; its acidity

The property D measured, was a physical property of X; its density

The property V measured, was a physical property of X; it's viscosity probably.

Explanation:

1. The property V that was measured is the acidity of X. The acidity of X is a measure of the concentration of hydrogen ions present in it. When drops of another solution, containing dissolved sodium hydroxide, are slowly added, and a pH indicator is used to determine when the sodium hydroxide has completely reacted with X, the procedure determines the concentration of X that would neutralize the base, sodium hydroxide.

2. The property of X determined in the step is the density of X, a physical property. First the volume of X was determined by the displacement method. Then the density of X is calculated from its mass and volume.

3. Since during the determination of the property V, there was no alteration done to the chemical constitution of X, the property thus determined is a physical property. Melting of the sample is a physical change and likewise its flow rate through a very thin tube.

Answer:

An Alkane

Explanation:

Formula of ethane is CH3-CH3

Answer:

Ethane is the second member of

An alkane

Answer:

Carbon and oxygen are chemically bonded in it.

Explanation:

The other answer choices do not apply for compounds, but rather for mixtures instead.

Answer: 33.3 moles

Explanation: 67.2 g H2 = 67.2/2.016 = 33.3 moles

Answer:

Nonrenewable energy resources, like coal, nuclear, oil, and natural gas, are available in limited supplies. This is usually due to the long time it takes for them to be replenished. Renewable resources are replenished naturally and over relatively short periods of time

Answer

Using the law of reflection—the angle of reflection equals the angle of incidence—we can see that the image and object are the same distance from the mirror. This is a virtual image, since it cannot be projected—the rays only appear to originate from a common point behind the mirror.

Explanation:

Hope this helps someone

Answer:

K = [NH₃]¹⁶ [KHCO₃]¹⁴ / [CH₄]⁷ [N₂]⁸ [O₂]² [H₂O]¹⁷ [K₂CO₃]⁷

Explanation:

The equation for the reaction is given below:

7CH₄(g) + 8N₂(g) +2O₂(g) + 17H₂O(g) + 7K₂CO₃(s) —> 16NH₃(g) + 14KHCO₃(s)

Equilibrium constant (K) =..?

Equilibrium constant, K for a reaction is simply defined as the ratio of the concentration of the products raised to their coefficient to the concentration of the reactants raised to their coefficient.

Thus, the equilibrium expression for the Harber-Bosch process for the synthesis of ammonia can be written as shown below:

K = [NH₃]¹⁶ [KHCO₃]¹⁴ / [CH₄]⁷ [N₂]⁸ [O₂]² [H₂O]¹⁷ [K₂CO₃]⁷

Answer:

Partial pressures:

PCl₅ = 0.558 atm

PCl₃ = 0.22 atm

Cl₂ = 0.22 atm

Explanation:

From the given information:

The number of moles of PCl₅ associated with the evaporation is:

[tex]n_{PCl_5}= \dfrac {weight \ of \ PCl_5} {M.Wt. \ of \ PCl_5}[/tex]

[tex]n_{PCl_5}= \dfrac {2.69 \ g} {208.5 \ g/mol}[/tex]

[tex]n_{PCl_5}= 0.013 \ mol[/tex]

Temperature of the gas = 250° C = (250 + 273.15) K

= 523.15 K

Using the Ideal gas equation to determine the pressure exerted by the completely vaporized PCl₅

PV = nRT

[tex]P = \dfrac{nRT}{V}[/tex]

[tex]P = \dfrac{0.0013 \ mol \times 0.082 \ Latm^0 K^{-1} . mol ^{-1} \times 523.15 \ K}{1.0 \ L}[/tex]

P = 0.558 atm

Thus, at  250° C, decomposition of PCl₅ occurs.

In the container, PCl₅  decomposes to PCl₃ and Cl₂.

i.e.

[tex]PCl_{5(g)} \to PCl_{3(g)}+ Cl_{2(g)}[/tex]

Using Dalton's Law:

[tex]P_{total } =P_1 + P_2+P_3 +...[/tex]

[tex]P_1 = P_{Total} \times X_1[/tex]

where;

X = mole fraction

Then, the total no. of moles in the container is:

[tex]n = \dfrac{PV} {RT}[/tex]

[tex]n = \dfrac{1\ atm \times 1.0\ L}{0.0821 \ L \ atm \ K^{-1}.mol \times 523.15\ K}[/tex]

n = 0.023 mol

Now, the container contains a total amount of 0.023 mol where initially 0.013 mol are that of PCl₅ and remaining 0.005 mol of PCl₃ and 0.005 mol of Cl₂.

Thus, the partial pressure of  PCl₃  is:

[tex]P__{PCL_3} }= P_{total} \times \dfrac{no. \ of \ moles \ of PCl_5}{total \ no. \ of \ moles}[/tex]

[tex]P__{PCL_3}} = 1 \ atm \times \dfrac{0.005}{0.023}[/tex]

[tex]P__{PCL_3}} = 0.22 \ atm[/tex]

Thus, since the no of moles of PCl₃ and Cl₂ are the same, then the partial pressure for Cl₂ is = 0.22 atm

Answer:

pH = 6.76

Explanation:

Ka = 3.4x10⁻⁷; 3.0x10⁻⁵g

The molarity of the vitamin B1 -Molar mass: 327.268g/mol- solution is:

3.0x10⁻⁵g * (1mol / 327.268g) = 9.167x10⁻⁸M

The Ka expression is:

Ka = 3.4x10⁻⁷ = [H⁺] [B1-] / [B1]

Where B1- is the conjugate base of vitamin B1,

In equilibrium, the concentrations are:

[H⁺] = X

[B1-] = X

[B1] = 9.167x10⁻⁸M - X

Where X is reaction coordinate

Replacing:

3.4x10⁻⁷ = [X] [X] / [9.167x10⁻⁸M - X]

3.117x10⁻¹⁴ -3.4x10⁻⁷X = X²

3.117x10⁻¹⁴ -3.4x10⁻⁷X - X² = 0

Solving for X:

X = -4.15x10⁻⁷M. False solution. There is no negative concentrations.

That means from the equilibrium of vitamin B1, the [H⁺] = 7.51x10⁻⁸M

From the autoinoization of water:

[H⁺] = 1.0x10⁻⁷M

[H⁺] in the solution is:

1.0x10⁻⁷M + 7.51x10⁻⁸M = 1.751x10⁻⁸M

As pH = -log[H⁺]

Answer:

-1

Explanation:

According to this question, the oxidation state/number of H and O in C2H4O is +1 and -2 respectively.

The oxidation state of carbon in the compound can be calculated thus:

Where;

x represents the oxidation number of C

C2H4O = 0 (net charge)

x(2) + 1(4) - 2 = 0

2x + 4 - 2 = 0

2x + 2 = 0

2x = -2

Divide both sides by 2

x = -1

The oxidation number of C in C2H4O is -1.

Answer:

so basically you just

Explanation:

Answer:

The mass of a system does not change during a chemical reaction

Explanation:

Correct Answers

The empirical formula :

C₁₀H₁₆N₄SO₇

Given

6.4 g sample

Required

The empirical formula

Solution

mass C :

= 12/44 x 8.37 g

= 2.28

mass H :

= 2/18 x 2.75 g

= 0.305

mass N = 1.06

mass S :

= 32/64 x 1.23

= 0.615

mass O = 6.4 - (2.28+0.305+1.06+0.615) = 2.14 g

Mol ratio :

= C : H : N : S : O

= 2.28/12 : 0.305/1 : 1.06/14 : 0.615/32 : 2.14/16

= 0.19 : 0.305 : 0.076 : 0.019 : 0.133 divided by 0.019

= 10 : 16 : 4 : 1 : 7

The empirical formula :

C₁₀H₁₆N₄SO₇

Answer:

1.6734 g\ml..hope it helps

Explanation:

H2SO3 is more acid than H2TeO3. Since S is more electronegative than Te is. In H2SO3, thus, dissociation of H+ would be smoother.

So, H2SO3's got high Ka.

HCH3SO2 is more acid than HCH3CO2. Since S is more electronegative than C. So, HCH3SO2 is a high Ka.

HClO2 is more acid than HClO. Since in HClO2, after the donation of H+ ion, the negative charge is set by two oxygen atoms, while in HClO, only one oxygen atom stabilizes the negative charge.

So, HClO2 is a high Ka

Explanation:

Molar mass of AlCl3 = 133.34g/mol

Moles of AlCl3 used

= 20.0g / (133.34g/mol) = 0.150mol

Mole Ratio of AlCl3 to Cl2 = 2 : 3,

Moles of Cl2 produced

= 0.150mol * (3/2) = 0.225mol

We know that 1 mole of any gas has

6.023 * 10²³ molecules.

Hence, number of molecules in Cl2

= 0.225mol * (6.023 * 10²³/mol)

= 1.35 * 10²³ molecules. (C)

Answer:

A,

C.

D.

B.

Explanation:

The front vent of a fume hood that assists and maintain proper air circulation is Airfoil

The horizontal flat surface area of the fume hood where experiments are being carried out is Work  Surface.

The main characteristics which demonstrate and describes how substances evaporate rapidly and readily into the thin air while producing a huge amount of vapor is known as Volatile

In front of the fume hood, lies the glass panel whose main purpose is to shield the user from the hazardous substance. This glass panel is known as the Sash.

Answer:

The right one.

Explanation:

The right one looks like it is getting the most sun.

Answer:

Mg is the limiting reactant.

52.9 g of FeCl₃, remains after the reaction is complete.

Explanation:

First of all, we state the reaction's equation:

3Mg (s) + 2FeCl₃ (aq) → 2Fe (s) + 3MgCl₂ (s)

We determine the mol of each reactant:

43.5 g . 1mol / 24.3g = 1.79 mol of Mg

247 g . 1mol/ 162.2g = 1.52 mol of Iron (III) chloride.

Ratio is 2:3. 2 mol of chloride need 3 moles of Mg to react,

Then 1.52 moles will react with (1.52 . 3) /2 = 2.29 moles

We have 1.79 moles of Mg and we need 2.29, so the limiting reactant is the Mg.

We confirm the chlorine as the excess reactant:

3 moles of Mg need 2 moles of FeCl₃ to react:

1.79 moles of Mg will react to (1.79 . 2) /3  = 1.19 moles of FeCl₃

We have 1.52 moles of FeCl₃ and we only need 1.19, so it is ok, we said that the FeCl₃ is the excess.

After the reaction goes complete, (1.52 - 1.19) moles of FeCl₃ remains.

1.52 - 1.19 = 0.33 moles. We convert them to mass:

0.33 mol . 162.2g /1mol = 52.9 g