A 50.0-ml volume of 0.15 m hbr is titrated with 0.25 m koh. calculate the ph after the addition of 14.0 ml of koh. express your answer numerically.

When 48.6 g of water vaporizes at its boiling point (100.0 °C), the change in the entropy is 0.292 kJ/K.

First, we will calculate the change in the enthalpy (ΔH) when 48.6 g of water vaporizes considering the following relationships.

[tex]\Delta H = 48.06 g \times \frac{1mol}{18.02g} \times \frac{40.7kJ}{mol} = 109kJ[/tex]

Then, we will convert 100.0 °C (T) to Kelvin using the following expression.

[tex]T = K = \° C + 273.15 = 100.0\° C + 273.15 = 373.2 K[/tex]

Finally, we will calculate the change in the entropy (ΔS) for this process using the following expression.

[tex]\Delta S = \frac{\Delta H }{T} = \frac{109kJ}{373.2K} = 0.292kJ/K[/tex]

When 48.6 g of water vaporizes at its boiling point (100.0 °C), the change in the entropy is 0.292 kJ/K.

Learn more: https://brainly.com/question/13146879

A 3.1 L sample of hydrogen at the same temperature and pressure as 0.20 mol of CO₂ will also contain 0.20 mol of hydrogen.

To answer the question, we need to understand the relationship between volume, temperature, and pressure for gases, as explained by the Ideal Gas Law.

The Ideal Gas Law is given by the equation PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature in Kelvin.

Since we are told that the volume sample of hydrogen is at the same temperature and pressure as the carbon dioxide, we can directly relate the two based on their moles.

For carbon dioxide (CO₂):

n = 0.20 mol

V = 3.1 L

This relationship tells us that 0.20 moles of CO₂ occupies 3.1 L at the given temperature and pressure.

Applying the same conditions to hydrogen (H₂), a 3.1 L sample of hydrogen gas will contain the same number of moles as the CO₂ under the same conditions:

0.20 mol of Hydrogen (H₂)

Therefore, 3.1 L of hydrogen at the same temperature and pressure will also contain 0.20 mol of hydrogen gas.

Answer:

Geiger counter and scintillation counter

Explanation:

The Geiger counter was invented by Hans Geiger in 1908 to measure the levels of radiation in bodies and the environment, so it is one of the indispensable equipment for the inspector to detect radiation leaks in a nuclear power plant. It contains a tube with argon, which ionizes by being crossed by alpha and beta particles of radiation, closing the electric circuit and triggering the counter.

Similarly, a scintillation detector is an apparatus used to detect ionizing radiation. When something in the environment has been reached by radiation, this detector emits a small ray of light, indicating the radiation contamination.

Answer:

A. Geiger counter and scintillation counter

Explanation:

When a strong monoprotic acid is Titrated with a weak base at 25° ;

A monoprotic acid donates only a single proton in a titration experiment therefore at the equivalence point in an experiment involving the reaction between the strong monoprotic acid with a weak base, all the base ions will react, while the strong acid will have some unreacted ions  ( H⁺) left in the solution.

The unreactive protons of the strong monoprotic acid present in the solution will make the solution acidic therefore the pH of the solution will be less than 7 at the equivalence point.

Hence we can conclude that when a strong monoprotic acid is titrated with a weak base at 25°, the pH will be less than 7 at the equivalence point.

Learn more : https://brainly.com/question/22763666

Final answer:

In a titration of a monoprotic strong acid with a weak base, the pH will be less than 7 at the equivalence point because the conjugate acid of the weak base will slightly ionize, rendering the solution acidic at this point.

Explanation:

When titrating a monoprotic strong acid with a weak base at 25°C, the pH at the equivalence point will be less than 7. This is because the reaction at the equivalence point produces the conjugate acid of the weak base, which slightly ionizes in solution, contributing to an acidic pH. As outlined in resources such as LibreTexts, the equivalence point's pH depends on the strength of the acid and base involved in the titration. In the case of a strong acid with a weak base, the solution will be acidic because the weak base is not strong enough to fully neutralize the strong acid. Therefore, the correct answer to the question is a. pH will be less than 7 at the equivalence point. It is also important to note that the number of moles of base and acid required to reach the equivalence point depends solely on their stoichiometry and not on their strength, meaning one mole of acid will react with one mole of base to reach the equivalence point.

Final answer:

Oxidation reactions during the electrolysis of water produce oxygen gas (O₂) at the anode. The process requires an electrolytic cell with an electrolyte such as sulfuric acid to facilitate the reaction, and it results in a stoichiometric ratio with twice the volume of hydrogen gas produced compared to oxygen gas.

Explanation:

During the electrolysis of water, oxidation reactions occur at the anode, producing oxygen gas (O₂). The reaction involves water molecules losing electrons to form oxygen gas and hydrogen ions. The overall chemical reaction for the oxidation process at the anode can be represented as 2H₂O(l) → O₂(g) + 4H⁺ + 4e⁻. Oxygen gas is released at the anode, while hydrogen gas is produced at the cathode.

In an electrolytic cell with platinum electrodes and an electrolyte like sulfuric acid (H₂SO₄), water undergoes electrolysis to form these gases. It's worth noting that there are twice as many hydrogen atoms as oxygen atoms, and because they are both diatomic (exist as H₂ and O₂), twice the volume of hydrogen gas is produced compared to oxygen gas. This stoichiometric relationship is essential for understanding the mass and volume ratios of the gases produced during water electrolysis.

Answer is: the freezing point of the solution of glucose is -1.26°C and boiling point is 100.353°C.
m(H₂O) = 455 g ÷ 1000 g/kg = 0.455 kg.
m(C₆H₁₂O₆) = 55.8 g. 

n(C₆H₁₂O₆) = m(C₆H₁₂O₆)÷ M(C₆H₁₂O₆).
n(C₆H₁₂O₆) = 55.8 g ÷ 180.16 g/mol.
n(C₆H₁₂O₆) = 0.31 mol.
b(solution) = n(C₆H₁₂O₆) ÷ m(H₂O).
b(solution) = 0.31 mol ÷ 0.455 kg.
b(solution) = 0.68 mol/kg.
ΔTf = b(solution) · Kf(H₂O).
ΔTf = 0.68 mol/kg · 1.86°C·kg/mol.

ΔTf = 1.26°C.
Tf = 0°C - 1.26°C = -1.26°C.

ΔTb = b(solution) · Kb(H₂O).

ΔTb = 0.68 mol/kg · 0.52°C·kg/mol.

ΔTb = 0.353°C.

Tb = 100°C + 0.353°C.

The boiling point of the solution is 100.35 °c.

We know that;

ΔT = K m i

ΔT = freezing point depression

K = freezing constant

m = molality

i = Van't Hoff factor

Hence;

ΔT =  1.86°c kg/mol × 55.8 g/180 g/mol × 1/0.455 × 1

ΔT = 1.27 °c

Freezing point = 0 - 1.27 °c = - 1.27 °c

For boiling point;

ΔT = K m i

ΔT = 0.512 o c kg × 55.8 g/180 g/mol × 1/0.455 × 1

ΔT = 0.35 °c

Boiling point = 100 +  0.35 °c = 100.35 °c

Learn more about freezing point: https://brainly.com/question/2292439

Answer;

-past temperatures

The ratio of oxygen-16 and oxygen-18 isotopes in plankton fossils in deep-sea sediments can be used to determine past temperatures.

Explanation;

-O-16 will evaporate more readily than O-18 since it is lighter, therefore; during a warm period, the relative amount of O-18 will increase in the ocean waters since more of the O-16 is evaporating.

-Hence, looking at the ratio of O16 to O18 in the past can give clues about global temperatures.

Answer:

The rate would be one-fourth. I just did it

Explanation:

For the reaction a(g) + 2b(l) = 4c(g) + d(g), the equilibrium constant expression using partial pressures, Kp, is Kp = (Pc)^4 (Pd) / (Pa).

To write the equilibrium-constant expression, Kp, for the reaction a(g) + 2b(l) = 4c(g) + d(g), we apply the principles of equilibrium for gases. Kp is an equilibrium constant calculated from partial pressures of gas-phase reactants and products at equilibrium. The liquids are not included in the Kp expression since their activities are considered constants under standard conditions and do not affect the equilibrium of gases.

The general form of an equilibrium constant expression for a reaction is Kp = (Pc)c (Pd)d / (Pa)a (Pb)b, where P represents the partial pressure of each gas, the lower-case letters right below the P are the chemical species, and the upper-case letters indicate the stoichiometric coefficients from the balanced equation.

Using the reaction given, we write the Kp expression as follows:

Kp = (Pc)4 (Pd) / (Pa)

Note that in our Kp expression, we do not include B since it is in the liquid state.

In the following reaction, the nitrogen is reduced.
2Cu2O + 2NO → 4CuO + N2

Answer:

Two nonmetals with the same electronegativity will form a non polar covalent bond.

Explanation:

The type of bond between atoms is classified in 3 big groups:

Apart from that, depending on the electronegativity difference, the covalent bonds are clasified in polar and non polar:

- Polar covalent bond: the difference of electronegativity is important but less than an ionic bond (between 0 and 2).

- Non polar covalent bond: this occurs when the atoms forming bonds have the same electronegativity.

So, analyzing the statement, if we have two nonmetals it is a covalent bond, and if the two nonmetals atoms have the same electronegativity the bond will be non polar.

In order to balance the equation, we identify the oxidation and reduction half-reactions and then combine them. The smallest possible integer coefficient of O₂ in the balanced equation is 10.

To balance the given equation cl2o7(g) + h2o2(aq) → clo− 2 (aq) + o2(g), we first have to identify the oxidation and reduction half-reactions. The oxidation half-reaction is: Cl₂O₇ → 2ClO₂⁻ + 5/2O₂. The reduction half-reaction is: H₂O₂ + 2e⁻ → 2OH⁻. Then, we combine the oxidation and reduction half-reactions: 4 Cl₂O₇ + H₂O₂ → 8 ClO₂⁻ + 2OH⁻ + 10O₂. The smallest possible integer coefficient of O₂ in the combined balanced equation is 10.

https://brainly.com/question/13978139

#SPJ12

The process of balancing redox reactions involves separating the reaction into two half-reactions, balancing them individually, and then combining them to ensure the total charges cancel out. In the given reaction, Cl2O7(g) + H2O2(aq) → ClO2−(aq) + O2(g), the smallest possible integer coefficient of O2 is 1 as one molecule of H2O2 produces one molecule of O2.

To balance the given redox reaction, Cl2O7(g) + H2O2(aq) → ClO− 2(aq) + O2(g), we split into two half-reactions, one for oxidation, and one for reduction. Assign oxidation numbers to identify which atoms have changed oxidation state during the reaction. The oxidation half-reaction can be identified as H2O2(aq) → O2(g) and the reduction half-reaction as Cl2O7(g)  → ClO− 2(aq).

Balance each of these half-reactions, first for atoms other than hydrogen and oxygen, then for oxygen, then for hydrogen, and lastly for charge. After balancing the half-reactions individually, combine them ensuring the total charges cancel out. The smallest integer coefficient of O2 in balanced equation results from the oxidation half-reaction, where one molecule of H2O2 produces one molecule of O2, thus the smallest possible integer coefficient of O2 is 1.

https://brainly.com/question/31991118

#SPJ11

To find the number of atoms in 0.530 g of P2O5, you calculate the number of moles by dividing by the molar mass and then multiply by Avogadro's number, resulting in approximately 2.25 × 1021 atoms.

To determine the number of atoms in 0.530 g of P2O5, we need to calculate the number of moles and then multiply by Avogadro's number (6.022 × 1023 atoms/mol). The molecular weight of P2O5 is found by adding the atomic weights of its constituent atoms: 2P (2 × 30.973761 amu/atom) + 5O (5 × 15.9994 amu/atom), which gives us approximately 141.94 amu. Since molar mass is the mass of one mole of a substance, we can say P2O5 has a molar mass of about 141.94 g/mol.

Now, to find moles, we divide the given mass by the molar mass:
0.530 g / 141.94 g/mol = 0.00373 mol.
Next, we multiply the moles by Avogadro's number to get the total atoms:
0.00373 mol × 6.022 × 1023 atoms/mol = 2.25 × 1021 atoms.

The answer is true. I just had this question on a test and I got it wrong for saying false.

Here we have to judge the statement about the hydrogen bond is true or false for water molecule.

The both the statement about hydrogen bonding in water is true i.e. The water molecule can act as hydrogen-bond donor and acceptor.

The hydrogen bond is a weak interaction between a hydrogen atom and an electronegative atom.

In water (H₂O) there remains hydrogen atom (H) and also the electronegative atom oxygen (O). The donor property and acceptor property to produce hydrogen bond in water is shown in figure.

The donor and acceptor property of water is shown in the figure.

The correct answer is true.

Hope this helps! ;)

Boron and Oxygen, due to their similar electronegativity can form a nonpolar covalent bond. This type of bond is formed when electrons are shared equally between atoms. Sodium and Chlorine, with their contrasting electronegativities, would rather form an ionic bond.

The atom pairs that form a nonpolar covalent bond from the options given would be B and O. Boron (B) and Oxygen (O) come from nonmetals with similar electronegativity, hence they share electrons equally forming a nonpolar covalent bond.

Nonpolar covalent bonds form when two atoms share electrons equally, meaning the electrons spend an equal amount of time around each atom. This could involve two atoms of the same element, like O₂, or atoms of different elements with similar electronegativity, like CH4 (methane).

On the contrary, atoms like Sodium (Na) and Chlorine (Cl), have a large difference in electronegativity, leading to an ionic bond instead of a covalent bond. In such cases, a clearly positive (cation) or negative (anion) charge develops on the atoms.

https://brainly.com/question/14470991

#SPJ6

The correct answer is: E) None of the above  atoms form a nonpolar covalent bond.

For a nonpolar covalent bond to form, the atoms involved must have similar electronegativities, typically seen in diatomic molecules of the same element

Given options:

A) Na and Cl - This forms an ionic bond.

B) C and O - This forms a polar covalent bond.

C) N and Cl - This forms a polar covalent bond.

D) B and O - This forms a polar covalent bond.

Full question

Which pair of atoms forms a nonpolar covalent bond?

A) Na and Cl  

B) C and O  

C) N and Cl  

D) B and O

E) None of the above.

Answer :  The total number of molecules in 0.5 mole of sample of He gas are, [tex]3.011\times 10^{23}[/tex]

Explanation : Given,

Moles of sample of He gas = 0.5 mole

As we know that,

1 mole of gas contains [tex]6.022\times 10^{23}[/tex] number of molecules of gas

As, 1 mole of He gas contains [tex]6.022\times 10^{23}[/tex] number of molecules of He gas

So, 0.5 mole of He gas contains [tex]0.5\times (6.022\times 10^{23})=3.011\times 10^{23}[/tex] number of molecules of He gas

Therefore, the total number of molecules in 0.5 mole of sample of He gas are, [tex]3.011\times 10^{23}[/tex]

About 15.20g of silver would have to be dissolved in 1120 g of ethanol to lower the freezing point by 0.25°C.

To find out how many grams of silver need to be dissolved in 1120 g of ethanol to lower its freezing point by 0.25°C, we can use the formula for freezing point depression:

[tex]\Delta T_f = K_f \cdot m[/tex]

Where:

Step 1: Calculate Molality (m)

Step 2: Calculate Moles of Silver Required

Using the definition of molality:

Thus:

Step 3: Convert Moles to Grams

Therefore, approximately 15.20 grams of silver would need to be dissolved in 1120 g of ethanol to lower the freezing point by 0.25°C.

The given reaction of metallic sodium with sulphur involves two electrons which are lost  from two sodium atoms and gained by the sulphur atom. Thus sodium atom oxidizes from 0 to +1 and sulphur reduces from 0 to -1.

A redox reaction involves oxidation of one reactant species and reduction of other species. The species which loss or donate electrons are oxidized to higher oxidation states whereas, the species which gain one or more electrons are reduced to lower oxidation states.

Metals are electron rich and will lose electrons easily to a non-metal during chemical bonding. Here the valency of sulphur is two thus it needs to gain 2 electrons. One sodium donate one electrons and thus two sodium atoms are needed to react with sulphur.

The oxidation reaction here is :

[tex]\rm 2 Na \rightarrow 2Na^{+} + 2 e^{-}[/tex]

Reduction of sulphur is written as:

[tex]\rm S + 2e ^{-} \rightarrow S^{2-}[/tex]

Therefore, the number of electrons involved in this oxidation -reduction reaction is 2.

To find more on redox reactions, refer here:

https://brainly.com/question/13978139

#SPJ2

To find the  moles equivalent to 2.50x10²⁰ atoms of Fe, you divide the given number of atoms by Avogadro's number (6.022x10²³ atoms/mole). This yields approximately 0.415 moles of Fe.

To calculate the number of moles equivalent to 2.50x10²⁰ atoms of Fe (Iron), you can use Avogadro's number, which is 6.022x10²³ atoms/mole. Let's divide the given no. with Avogadro's number. Let's do the computation:

2.50x10²⁰ atoms Fe * (1 mol Fe / 6.022x10²³ atoms Fe) = ~0.415 moles of Fe

This means that 2.50x10²⁰ atoms of Fe is equivalent to 0.415 moles. Avogadro's number is a fundamental constant in chemistry and is used to convert between the atomic scale and macroscopic scale.

https://brainly.com/question/33720401

#SPJ12

2.50x10^20 atoms of Fe are equivalent to approximately 4.15x10^-4 moles. This is calculated by dividing the number of atoms by Avogadro's number (6.022x10^23 atoms per mole).

To calculate how many moles are equivalent to 2.50x10^20 atoms of Fe, we use Avogadro's number, which states that one mole of any substance contains 6.022x10^23 elementary entities (like atoms). Therefore, to convert the number of atoms to moles, we divide the number of atoms by Avogadro's number.

In this case, (2.50x10^20) / (6.022x10^23), which equals approximately 4.15x10^-4 moles of Fe.

https://brainly.com/question/8512069

#SPJ12

Final answer:

To determine the actual yield of ammonia gas, convert the mass of nitrogen gas to moles, calculate the theoretical yield using stoichiometry, and then apply the percent yield. The actual yield for a 68.2% percent yield from 2.00 kg of nitrogen is 1658.41 g NH3.

Explanation:

To calculate the actual yield of ammonia gas (NH3) production from nitrogen (N2) and hydrogen (H2) gases when given the percent yield and mass of nitrogen gas, we'll first need to convert the mass of nitrogen to moles, then calculate the theoretical yield of ammonia based on stoichiometry, and finally use the percent yield to find the actual yield.

Step-by-step Calculation:

Calculate moles of nitrogen: Molecular weight of N2 is 28.02 g/mol. 2.00 kg of N2 is 2000 g. Moles = 2000 g / 28.02 g/mol = 71.38 mol N2.

Using the balanced chemical equation (N2 + 3H2 → 2NH3), we see the stoichiometry is 1:2 for nitrogen to ammonia. So, moles of NH3 = 2 moles NH3/mole N2 × 71.38 mol N2 = 142.76 mol NH3.

Convert moles of NH3 to grams: Molecular weight of NH3 is 17.03 g/mol. The theoretical yield in grams = 142.76 mol NH3 × 17.03 g/mol = 2431.89 g NH3.

Calculate actual yield using the percent yield: Actual Yield = Percent Yield / 100 × Theoretical Yield = 68.2% / 100 × 2431.89 g = 1658.41 g NH3.

Therefore, the actual yield of ammonia when starting with 2.00 kg of nitrogen gas and a percent yield of 68.2% is 1658.41 g.