Explain why I2 is a solid, Br2 is a liquid but Cl2and F2 are gases even though they are all Halogens

Explanation:

1. Methane

2. Diamond

3. not sure : )

Answer:

resistance becomes lower at higher temperatures.

Explanation:

molecules expand instead of compact

Number of Br atoms : 2.679 x 10²³

The mole is the number of particles contained in a substance

1 mol = 6.02.10²³

Moles can also be determined from the amount of substance mass and its molar mass

\(\tt mol=\dfrac{mass}{MW}\)

Proust stated the Comparative Law that compounds are formed from elements with the same Mass Comparison so that the compound has a fixed composition of elements

\(\tt mass~Br=\dfrac{2.Ar~Br}{MW~CH_2Br_2}\times mass~CH_2Br_2\\\\mass~Br=\dfrac{2.80}{174}\times 38.7=35.59~g\)

\(\tt \dfrac{35.59}{80}=0.445\)

\(\tt 0.445\times 6.02\times 10^{23}=\boxed{\bold{2.679\times 10^{23}}}\)

Explanation:

Plate tectonics is a theory derived from the theory of sea floor spreading and continental drift.

The theory proposes that the outer layer of the earth is broken down into series of slabs that moves over the mantle.

This outer layer of the earth is called the lithosphere. The lithosphere is made up of the crust and the upper mantle.

The layer below the lithosphere which allows for the movement of the lithosphere is called the asthenosphere.

In the test we have a 10/10 fraction of questions, which could also mean 100%, if Rita answered 9 questions correctly, we have a fraction of 9/10, which is 90%, therefore she answered 1 question incorrectly, the fraction will be 1/10, which represents 10% of the test. The option will be C 1/10

The molarity of the KCl solution is 4.04 moles/ litre

Molarity (M), which is determined by dividing the solute's mass in moles by the volume of the solution in liters, is the most widely used unit to express solution concentration: liters of solution/moles of solute equals M. One liter of a solution with a 1.00 molar concentration (1.00 M) contains 1.00 moles of solute.

The amount of a substance in a specific volume of solution is known as its molarity (M). The number of moles of a solute per liter of a solution is known as molarity. The molar concentration of a solution is another name for molarity.

Molarity = no. of moles/ volume of solution

Volume of KCl solution given is 0.25 L

molarity = 1.01 / 0.25

molarity = 4.04 moles/ litre

TO know more about molarity you may visit the link:

https://brainly.com/question/8732513

#SPJ4

Answer:

ethyl methyl ether

Explanation:

when naming ethers name the alkyl rings, in this case we have methyl and ethyl( make sure they are in alphabetical order) followed by the word ether, so it becomes ethyl methyl ether

In order to dissolve a chemical sample in a recrystallization solvent, add the room-temperature solvent just until it covers the sample in an Erlenmeyer flask on a hot plate.

Recrystallization involves dissolving the material to be purified (the solute) in an appropriate hot solvent.

Recrystallization, also known as fractional crystallization, is a procedure for purifying an impure compound in a solvent.

The method of purification is based on the principle that the solubility of most solids increases with increased temperature. Small crystals may trap impurities.

Thus, in order to dissolve a chemical sample in a recrystallization solvent, add the room-temperature solvent just until it covers the sample in an Erlenmeyer flask on a hot plate. Turn on the heat, starting at a low setting and increasing gradually.

Learn more about the recrystallization solvent here:

https://brainly.com/question/14918321

#SPJ1

For a given sample of ch3oh , the enthalpy change during the reaction is 82.7 kj. The mass of the methane gas will be 32 gram.

When methanol will provide some temperature, then it will break into methane and oxygen gas and release some amount of energy.

The balanced chemical equation can be written as:

\(2CH_{3}OH\)→ \(2CH_{4} + O_{2}\), ΔH= 82 kJ

It can be seen that 2 mole of methane will produce 82 kj energy.

Hence, the energy of 82.3kj the count of mole could be = (2×82.3)/82

 = 2 moles

The mass will be equivalent to the = 2 × 16 = 32 g

Therefore, the mass of \(CH_{4}\) produced will be 32g

To know more about enthalpy change

https://brainly.com/question/24259325

#SPJ4

The given statement suggests that CaCl₂ is dissolved in water. We are required to identify which of the given steps is not involved in this solvation process.

The three steps involved in the solvation process are dissociation, ionization, and hydration. Out of these three steps, ionization is not involved in the solvation process of CaCl₂ in water.Ionization is the process of forming ions by losing or gaining electrons, whereas dissociation is the separation of a molecule into ions.

Hydration is the process in which ions of an ionic compound get surrounded by water molecules in solution. When CaCl₂ is dissolved in water, it dissociates into its respective ions, Ca²⁺ and 2Cl⁻. Hence, dissociation and hydration occur during the solvation process of CaCl₂ in water.

Therefore, the answer to this question is that ionization is not involved in the solvation process of CaCl₂ in water.In conclusion, CaCl₂ dissolves in water through dissociation and hydration processes.

Dissociation separates it into Ca²⁺ and 2Cl⁻ ions, whereas hydration involves the surrounding of these ions by water molecules. Ionization is not involved in the solvation process of CaCl₂ in water.

To know more about solvation process click on below link:

https://brainly.com/question/1118783#

#SPJ11

Answer:

D or 4

Explanation:

right on edge 2021

Answer:

d

Explanation:

a) The absolute standard deviation of the concentration of NaOH is 0.0041 M.

b) The standard error of the concentration of NaOH is 0.0018 M.

c) The confidence interval of the concentration of NaOH is (0.1033 M, 0.1060 M).

d) Yes, the sample mean is significantly different from the true concentration of 0.1045 M.

e) No, the mean concentrations from the two students' results are not similar to each other.

a) To calculate the absolute standard deviation of the concentration of NaOH, we need to find the standard deviation of the given data points. Using the formula for sample standard deviation, we calculate the average deviation of each data point from the mean concentration, then square each deviation, take the average of the squared deviations, and finally, take the square root. The absolute standard deviation is the absolute value of the standard deviation.

b) The standard error of the concentration of NaOH measures the variability of the sample means from different samples. It is calculated by dividing the standard deviation by the square root of the sample size. In this case, the sample size is 5.

c) To calculate the confidence interval of the concentration of NaOH, we need to determine the margin of error using the t-distribution and the sample standard deviation. With a 95% confidence level, we use a t-value corresponding to 4 degrees of freedom (n-1) and multiply it by the standard error. The confidence interval is constructed by subtracting and adding the margin of error to the sample mean concentration.

d) To determine if the sample mean is significantly different from the true concentration, we compare the true concentration to the confidence interval. If the true concentration falls outside the confidence interval, then the sample mean is significantly different from the true concentration.

e) To assess if the mean concentrations from the two students' results are similar to each other, we can calculate the confidence intervals for each student's data. If the confidence intervals overlap or are close to each other, it suggests that the mean concentrations are similar. However, if the confidence intervals do not overlap, it indicates that the mean concentrations are likely different.

Learn more about concentration

brainly.com/question/18247103

#SPJ11

Answer:

a

Explanation:

as the earth rotate around the sun it appears to be moving across the sky

Answer:

The answer is option A

Explanation:

From Earth, the Sun looks like it moves across the sky in the daytime and appears to disappear at night. This is because the Earth is spinning towards the east. The Earth spins about its axis, an imaginary line that runs through the middle of the Earth between the North and South poles.

Please mark me brainliest

5) Convert molarity to percent, calculate moles of acetic acid, convert moles to grams, divide grams by volume in mL, multiply by 100 to obtain experimental percent, and calculate percent error.

6) Phenolphthalein could have been used as an alternative indicator.

7) When using barium hydroxide instead of sodium hydroxide, adjust the calculations by considering the stoichiometry of the reaction and using a molar ratio of 2:1 between acetic acid and barium hydroxide.

5. To calculate the percent error in the concentration of acetic acid, we need to convert our molarity (M) results to percent (%). Using the average molarity and the average volume (converted to liters) of acetic acid, we can calculate the number of moles of acetic acid.

Then, by converting moles to grams using the molar mass of acetic acid (CH3COOH), we can divide the grams of acetic acid by the average volume (in milliliters) of acetic acid and multiply by 100 to obtain the experimental percent.

Finally, we can calculate the percent error by comparing the experimental percent to the labeled percent (4% vinegar on the bottle).

6. An alternative indicator that could have been used is phenolphthalein. Phenolphthalein is commonly used in acid-base titrations and changes color in a specific pH range, indicating the endpoint of the reaction.

6. If barium hydroxide (Ba(OH)2) were used instead of sodium hydroxide (NaOH), the adjustment in calculations would involve the stoichiometry of the reaction. The balanced chemical equation for the reaction between acetic acid and barium hydroxide is:

2CH3COOH + Ba(OH)2 → Ba(CH3COO)2 + 2H2O

The molar ratio between acetic acid and barium hydroxide is 2:1. Therefore, the number of moles of barium hydroxide used would be half the number of moles of acetic acid in the calculation.

The rest of the procedure, including converting moles to grams and calculating the percent, would remain the same.

For more such questions on molarity visit:

https://brainly.com/question/30404105

#SPJ8

Answer:

C

Explanation:

The reaction has a heat of 161.1 kJ/mol.

If 250 mL of a NaOH solution contain 1 milligrams of NaOH, the solution's molarity is 10-4 M. The amount of solute in 1 litre of solution is known as the molarity.

We can use the following formula to get the reaction's heat:

Q = m × c × ΔT

The total volume of the mixture is 500.0 mL because we are aware that the volume of each solution is 250.0 mL:

m = V × ρ

m = 500.0 mL × 1.025 g/mL

m = 512.5 g

The change in temperature must then be calculated:

ΔT = (48.8°C - 2.0°C) = 46.8°C

Assuming that the acid used is HCl and the base used is NaOH, their molar masses are:

HCl: 1 mol of HCl = 36.46 g/mol

NaOH: 1 mol of NaOH = 40.00 g/mol

The reaction between HCl and NaOH has the following chemical formula:

HCl + NaOH → NaCl + H2O

As can be seen, the reaction's stoichiometry is 1:1, which means that 1 mole of HCl combines with 1 mole of NaOH.

So, the following formula can be used to determine the reaction's heat:

Q = m × c × ΔT

Q = 512.5 g × 4.190 J/goC × 46.8°C

Q = 100,697 J or 100.697 kJ

Since both solutions have a 2.500 M molarity, the number of moles of either HCl or NaOH can be determined as follows:

moles = M × V

moles = 2.500 mol/L × 0.2500 L

moles = 0.6250 mol

Therefore, the heat of the reaction is:

Q/mol = Q / moles

Q/mol = 100.697 kJ / 0.6250 mol

Q/mol = 161.1 kJ/mol

To know more about reaction visit:-

https://brainly.com/question/14025220

#SPJ1

The main difference between a colloid and solution lies in the size of the particles dispersed in the medium.

1. Colloid: A colloid is a mixture in which tiny particles (between 1 nanometer and 1 micrometer in size) are dispersed evenly throughout a continuous medium. The dispersed particles do not settle and remain suspended due to their relatively larger size. Examples of colloids include milk, fog, and gelatin.

2. Solution: A solution is a homogeneous mixture in which the particles are molecular or ionic in size (less than 1 nanometer) and are uniformly distributed throughout a solvent. The particles in a solution are so small that they do not scatter light, and the mixture appears transparent. Common examples of solutions include saltwater, sugar dissolved in water, and air.

In summary, the key distinction between a colloid and a solution lies in the size of the dispersed particles. Colloids have larger particles that remain suspended, resulting in a cloudy or opaque appearance, whereas solutions have much smaller particles that are molecular or ionic in size and result in a clear and transparent mixture. Understanding this difference helps to differentiate between these two types of mixtures in various scientific and everyday contexts.

To know more about colloid and solution click here:

https://brainly.com/question/29667002

#SPJ11

The total charge that flows while the battery is being charged is approximately 193,939.39 Coulombs.

To calculate the total charge that flows while the battery is being charged, we can use the relationship between electrical energy, potential difference, and charge.

The electrical energy (E) stored in the battery is given as 64 mega Jules (64 MJ). The potential difference (V) provided by the battery is 330 volts. We know that the energy (E) is equal to the product of the potential difference (V) and the charge (Q):

E = V * Q

Since the charging process is 100% efficient, all the electrical energy supplied is stored in the battery. Therefore, we can rearrange the equation to solve for the charge (Q):

Q = E / V

Substituting the given values, we have:

Q = 64 MJ / 330 V

To perform the calculation, we need to convert mega Jules (MJ) to joules (J) since the SI unit of energy is joules. One mega Joule is equal to 1 million joules:

Q = (64 * 10^6 J) / 330 V

Calculating the division:

Q ≈ 193,939.39 Coulombs

Therefore, the total charge that flows while the battery is being charged is approximately 193,939.39 Coulombs.

This value represents the quantity of electric charge transferred during the charging process, and it indicates the amount of electricity that enters the battery.

For more such questions on charge visit:

https://brainly.com/question/18102056

#SPJ8

Answer:

food

Explanation:

Shown below is a list of pairs of compounds. In which pair is the second compound produced by an oxidation of the first compound:

A. Pyruvate and phosphoenolpyruvate

B. Succinate and fumarate

C. Oxaloacetate and malate

D. Phosphoenolpyruvate and 2-phosphoglycerate

E. 1,3-bisphosphoglycerate and glyceraldehyde-3-phosphate

The pair of compounds in which the second compound is produced by an oxidation of the first compound is: B. Succinate and fumarate.
In the reaction from succinate to fumarate, an enzyme called succinate dehydrogenase oxidizes succinate, which results in the production of fumarate. This oxidation process involves the removal of two hydrogen atoms from succinate and the addition of a double bond between the two central carbon atoms, forming fumarate.

To know more about succinate dehydrogenase oxidizes succinate:

https://brainly.com/question/13943912

#SPJ11

Here are a few examples of energy transformations that occur in different scenarios, along with a detailed.

A battery-operated flashlight turned on:

When you turn on a battery-operated flashlight, the chemical energy stored in the battery is transformed into electrical energy, which is then transformed into light energy and thermal energy. The chemical energy stored in the battery is converted into electrical energy when you complete the circuit by pressing the button to turn on the flashlight. The electrical energy flows through the wires of the flashlight's circuit, which then powers the light bulb. The light bulb converts the electrical energy into light energy, which you can see, and thermal energy, which you can feel as heat.

Burning wood in a fireplace:

When you burn wood in a fireplace, the chemical energy stored in the wood is transformed into thermal energy and light energy. The chemical energy stored in the wood is released when it is burned, and this energy is transformed into thermal energy and light energy. The thermal energy is the heat that you feel when you stand near the fireplace, and the light energy is the glow that you see coming from the fire.

Photosynthesis in plants:

During photosynthesis, plants use light energy from the sun to transform carbon dioxide and water into glucose (a type of sugar) and oxygen. The light energy from the sun is absorbed by pigments in the plant's leaves, such as chlorophyll. This light energy is then transformed into chemical energy, which is used to power the reactions that convert carbon dioxide and water into glucose and oxygen. The glucose produced during photosynthesis is a form of potential energy that the plant can use for growth and other processes.

A hydroelectric dam:

A hydroelectric dam converts the potential energy of water stored in a reservoir behind the dam into electrical energy. The water stored behind the dam has gravitational potential energy, because it is held at a higher elevation than the turbines at the bottom of the dam. When the water is released from the reservoir and flows through the turbines, the gravitational potential energy is transformed into kinetic energy (the energy of motion). The turbines then use this kinetic energy to turn generators, which convert the mechanical energy into electrical energy that can be used to power homes and businesses.

To know more about energy transformation visit:

https://brainly.com/question/29102331

#SPJ1

The specific heat of the metal is approximately 0.169 J/g·°C.

To determine the specific heat of the metal, we can use the formula:

q = m * c * ΔT

where q is the heat energy absorbed by the metal, m is the mass of the metal, c is the specific heat of the metal, and ΔT is the change in temperature.

In this case, we have a mass of 25.0 g, a temperature change of 6.1 °C, and an energy input of 259 J.

Rearranging the formula, we can solve for c:

c = q / (m * ΔT)

Substituting the given values:

c = 259 J / (25.0 g * 6.1 °C)

c ≈ 0.169 J/g·°C

This value indicates that the metal requires 0.169 Joules of energy to raise the temperature of 1 gram of the metal by 1 degree Celsius. The specific heat value is a characteristic property of the metal and can be used to identify the metal or compare it to known values for different metals.

For more questions on specific heat

https://brainly.com/question/29792498

#SPJ8

Answer:

4.65 moles

Explanation:

1 mole ---> 6.022×10²³ atoms of si

X mole ---> 2.8×10²⁴ atoms of si

X= 2.8×10×10²³/6.022×10²³

=28/6.022

=4.65moles

Answer: It’s C for me: To synthesis new DNA

Explanation:

Brainly please

Answer:

1.3155M

Explanation:

molar mass of CuSO4

=63.55+32.07+16(4)

=159.62g/mol

n=mass/molar mass

n=42.00/159.62

n=0.2631mol

volume=200mL=0.2L

molarity=mole (n)/volume (v)

molarity=0.2631mol/0.2L

molarity=1.3155M

Answer: The pH is 9.09.

Explanation:

This question involves the hydrolysis of a salt into a weak acid and strong base.

The fastest solution is found by using the equation:

\(\text{pH} = \frac12 \ \text{pK}_w + \frac12 \ \text{pK}_a + \frac12 \log C\)

where C represents the concentration of the solution.

We have:

Ka = 1.34 x 10^-5, so pKa = -log(1.34 x 10^-5) = 4.873

Kw = 1.0 x 10^-14, so pKw = -log(1.0 x 10^-14) = 14.00

C = 0.20, so log(C) = log(0.20) = -0.70

Then,

\(\text{pH} = \frac12 (4.873) + \frac12 (14.00) + \frac12 (-0.70) = 9.09\)

A solution that uses only fundamental chemistry techniques can be found by considering the chemical reactions involved.

The salt \(\text{C}_2\text{H}_5\text{COONa}\) will completely dissolve in solution into its ions:

\(\text{C}_2\text{H}_5\text{COONa} \text{ (aq)} \rightarrow \text{C}_2\text{H}_5\text{COO}^- \text{ (aq)} + \text{Na}^+ \text{ (aq)}\)

This shows that \([\text{C}_2\text{H}_5\text{COO}^-] = [\text{C}_2\text{H}_5\text{COONa}] = 0.20 \text{ M}\).

When water is added, an acid-base reaction occurs:

\(\text{C}_2\text{H}_5\text{COO}^- \text{ (aq)} + \text{H}_2\text{O} \text{ (l)} \rightleftharpoons \text{C}_2\text{H}_5\text{COOH} \text{ (aq)} + \text{OH}^- \text{ (aq)}\)

Using a RICE (Reaction-Initial-Change-Equilibrium) table, we can write the following analysis:

0.20                       N/A                0                        0       (initial conc.)
- x                           N/A                + x                      + x    (change)
-------------------------------------------------------------------------
(0.20 - x)                N/A                 x                        x       (equilibrium)

Then, we can write the forward base-reaction constant:

\(\text{K}_b = \frac{[\text{C}_2\text{H}_5\text{COOH}][\text{OH}^-]}{[\text{C}_2\text{H}_5\text{COO}^-]} = \frac{(x)(x)}{0.20-x} = \frac{x^2}{0.20-x}\)

We have \(\text{K}_a = 1.34 \times 10^{-5}\) and we also know that \(\text{K}_w = \text{K}_a \times \text{K}_b\). It follows that:

\(\text{K}_b = \frac{\text{K}_w}{\text{K}_a} = \frac{1.0 \times 10^{-14}}{1.34 \times 10^{-5}} = 7.46 \times 10^{-10}\)

Since Kb is very small, we may assume that \((0.20 - x) \approx 0.20\). Then,

\(7.46 \times 10^{-10} = \frac{x^2}{0.20} \quad \rightarrow \quad x \approx \sqrt{0.20(7.46 \times 10^{-10})} = 1.22 \times 10^{-5}\)

Then,

\([\text{OH}^-] = x = 1.22 \times 10^{-5}\)

\(\text{pOH} = -\log(1.22 \times 10^{-5}) = 4.91\)

Finally,

\(\text{pH} = \text{pK}_w - \text{pH} = 14.00 - 4.91 = 9.09\)

When oil from a tin is poured through a funnel placed tightly into the neck of a bottle, the oil stays in the funnel because the air pressure inside the bottle prevents the oil from entering the bottle.

The force that air, whether compressed or unconfined, applies to whatever surface it comes into touch with is known as air pressure.

The air in the bottles exerts a force on the liquid that is to be poured inside it.

Since the air has no way of escaping, the oil cannot be poured into the bottle.

However, if a little space is allowed by the funnel for the air to escape, the liquid can then be poured into the bottle.

Learn more about air pressure at: https://brainly.com/question/12870338

#SPJ1

Answer:

4.7 x 10^14 Hz

Explanation:

From Bohr's theory, the energy absorbed or emitted (ΔE) by an atom transiting from one energy level to another is given as;

ΔE = E4 - E2

Where;

E4 = energy corresponding to the energy level n=4

E2 = energy corresponding to the level n= 2

ΔE = (-2.10 x 10-19) - ( - 5.20 x 10-19)

ΔE =3.1 x 10-19

But

ΔE = hf

h = Plank's constant

f= frequency of photon absorbed

f = ΔE/h = 3.1 x 10-19/6.6 x 10-34

f = 4.7 x 10^14 Hz

Answer:

Mass = 713.4 ×10⁻⁴ g

Explanation:

Given data:

Number of moles of calcium phosphate = 2.3×10⁻⁴ mol

Mass of calcium phosphate = ?

Solution:

Formula:

Number of moles = mass/molar mass

Molar mass of calcium phosphate is 310.18 g/mol

by putting values,

2.3×10⁻⁴ mol = mass / 310.18 g/mol

Mass = 2.3×10⁻⁴ mol × 310.18 g/mol

Mass = 713.4 ×10⁻⁴ g