PLEASE HELP ME ASAP DUE TODAY!!!!!!!!!!!!
4. A student performed an experiment to determine the density of a sugar solution and obtainedthe following results: 1.24 g/mL, 1.21 g/mL, 1.23 g/mL.The actual density is 1.50 g/mL. Circle the correct value for the average, X, in the first column and for the accuracy evaluation, RE(%), in the second column.

PLEASE HELP ME ASAP DUE TODAY!!!!!!!!!!!!4. A Student Performed An Experiment To Determine The Density

Answers

Answer 1

Answer:

1.23 g/mL

-18.2%

Explanation:

We need to find the average, which is just the sum of the numbers divided by the number of numbers. Here, the sum will be 1.24 + 1.21 + 1.23 = 3.68 g/mL. There are 3 numbers, so divide 3.68 by 3: 3.68 / 3 ≈ 1.2266...

However, we need to round this and take into account significant figures. Each trial gave a number with 3 significant figures, so we round our number off to three: 1.22666... ≈ 1.23. So, circle the first number under the X column.

We now need to find the percent error, which is RE (%). To calculate this, we take the measured value (1.23 in this case) and subtract the exact value (1.50 here) from it, and then divide that by the exact value:

(1.23 - 1.50) / 1.50 ≈ -0.1822...

Again, we need to round to 3 significant figures, which would make it:

-0.1822... ≈ -0.182

Thus, circle the last number under the RE (%) column.


Related Questions

Mr. Auric Goldfinger, criminal mastermind, intends to smuggle several tons of gold across international borders by disguising it as lumps of iron ore. He commands his engineer minions to form the gold into little spheres with a diameter of exactly and paint them black. However, his chief engineer points out that customs officials will surely notice the unusual weight of the "iron ore" if the balls are made of solid gold (density ). He suggests forming the gold into hollow balls instead, so that the fake "iron ore" has the same density as real iron ore. Calculate the required thickness of the walls of each hollow lump of "iron ore."

Answers

The given question is not complete, the complete question is:

Solving applied density problems Mr. Auric Goldfinger, criminal mastermind, intends to smuggle several tons of gold across International borders by disguising it as lumps of iron ore. He commands his engineer minions to form the gold into little spheres with a diameter of exactly 6 cm and paint them black However, his chief engineer points out that customs officials will surely notice the unusual weight of the "iron ore" if the balls are made of solid gold (density 19.3 g/cm'). He suggests forming the gold into hollow balls Instead (see sketch at right), so that the fake "Iron ore" has the same density as real iron ore (5.15 g/cm'). One of the balls of fake iron ore," sliced in half Calculate the required thickness of the walls of each hollow lump of iron ore. Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits.

Answer:

The correct answer is 0.29 cm.

Explanation:

To produce fake iron balls that is, formed of gold there is a need to make sure that the mass of the iron ball should be equivalent to the mass of the fake ball.  

To calculate the volume of iron ball with the help of the given diameter, the formula to be used is 4/3πr³. The diameter of the spheres mentioned in the given question is 6 cm, so the radius will be 6/2= 3 cm.  

Now, the volume of the iron ball would be = 4/3 × 3.14 × 3³ = 113.04 cm³

To determine the mass of the iron ball, the formula to be used is volume * density. Now putting the values we get,  

113.04 × 5.15 g/cm³ = 582.156 grams (The density of the iron ore is 5.15 g/cm³)

Now, the mass of the gold ball should also be equal to 582.156 g. The density of the solid gold is 19.3 g/cm³, therefore, the volume of the gold ball by using the above formula would be,  

mass of gold ball = Volume × density

Volume = mass of gold ball / density

Volume = 582.156 g / 19.3 g/cm³

= 30.1635 cm³

Thus, the volume of the hollow sphere would be 30.1635 cm³ with the outer radius as 3 cm, now there is a need to find the inner radius.  

Volume of hollow ball = 4/3π [R³ -r³]

30.1635 cm^3 = 4/3 pie [3³ = r³]

30.1635 × 3/4 × 3.14 = 27-r³

7.2046 = 27-r³

r³ = 19.7954

r = 2.7051 cm

Hence, the thickness would be outer radius - inner radius = 3-2.7051 = 0.2949 cm or 0.29 cm.  

Would you expect carboxylic acids with general formula CH3(CH2)nCOOH to become more or less water soluble as n increases? Explain.

Answers

Answer:

less soluble

Explanation:

As n increases, the non polar hydrocarbon tail increases in length, while there is only one polar carboxylic group at the end. Since only the carboxylic group can form hydrogen bond with water, and the non polar hydrocarbon tail cannot, the long tail will hinder the formation of hydrogen bond between acid and water molecules, hence solubility decreases.

The carboxylic acids with general formula CH3(CH2)nCOOH to become  less water soluble as n increases.

What is carboxylic acid ?

An organic acid that has a carboxyl group joined to an R-group is said to be carboxylic. A carboxylic acid's general formula is RCOOH or RCO2H, where R stands for an alkyl, alkenyl, aryl, or other group. Carboxylic acids are frequently present.

The carboxylic acids do not produce dimers when introduced to water. Instead, individual acid and water molecules create hydrogen bonds with one another. These interactions allow carboxylic acids to disintegrate in water to create acidic solutions.

Similar to how alcohols, aldehydes, and ketones are soluble in water, carboxylic acids are as well. Acids with fewer than five carbons dissolve in water; those with a higher molecular weight are insoluble because they include a greater proportion of hydrocarbons.

Thus, The carboxylic acids with general formula CH3(CH2)nCOOH to become  less water soluble as n increases.

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By means of a schematic diagram show how a bacteria cell applied to the region of a cowpea root can end up by becoming a nitrate ion which can be absorb by a subsequent crop.

Answers

Answer:

Nitrifying bacterium such as nitrosomonas or nitrobacter, whe applied to the soil, convert free ammonia or nitrogen to nitrates through oxidation. They are a group of aerobic bacteria playing an important role in the nitrogen cycle as producers of energy from inorganic source.

The schematic diagram attached summaries the action of such bacteria.

In the
Preparation of ethene from ethanol and
tetraoxosulphate (vi) acid, state
the concentration of the acid.​

Answers

Answer:

The acid must be a concentrated acid

Explanation:

Ethene is prepared in the laboratory by heating ethanol with excess concentrated tetraoxosulphate VI acid at 170°C . The reactionoccursc in two stages;

1) when the ethanol and sulphuric acid are mixed in a ratio of 1:2, ethyl hydrogentetraoxosulpate VI is formed

2) The compound formed in the first step is heated in the presence of excess concentrated sulphuric acid to give ethene and sulphuric acid.

The overall reaction can be perceived as the dehydration of ethanol. The gas produced (ethene) is usually passed through sodium hydroxide solution to remove any gaseous impurities present.

concentrated sulphuric acid is used in this process since it is a good dehydrating agent.

For many purposes we can treat propane as an ideal gas at temperatures above its boiling point of . Suppose the temperature of a sample of propane gas is lowered from to , and at the same time the pressure is decreased by . Does the volume of the sample increase, decrease, or stay the same? increase decrease stays the same If you said the volume increases or decreases, calculate the percentage change in the volume. Round your answer to the nearest percent.

Answers

Answer:

See explaination

Explanation:

please kindly see attachment for the step by step solution of the given problem

Calculate the pH of a solution having the following ion concentrations at 298 K. [H+] = 4.6 × 10^-2 M

Answers

Answer:

The pH of the solution is 1.34, being an acidic pH.

Explanation:

pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.   The acronym pH stands for hydrogen potential.

The pH scale ranges from 0 to 14. Values ​​less than 7 indicate the acidity range and those greater than 7 indicate alkalinity or basicity. Value 7 is considered neutral. Mathematically, pH is the negative logarithm of the molar concentration of hydrogen or proton ions (H⁺) or hydronium ions (H₃O⁺).

pH= - log [H⁺] = - log [H₃O⁺]

In this case, [H⁺]= 4.6*10⁻² M. Replacing:

pH= - log 4.6*10⁻²

Solving:

pH= 1.34

The pH of the solution is 1.34, being an acidic pH.

What is the difference between a strong electrolyte and a weak electrolyte

Answers

Answer:

One will give you more energy and the other will make you tired!

Explanation:

what structural units make up iconic solids

Answers

Answer:

the structural units are anions and cations bonded together by strong, non-directional ionic bonds

Olivia, a Latina student, is told that she can check only two books out of the library at a time, but Leann, a white student, is told that she can check out as many books as she wants. The best way for a white person to help end this type of white privilege is to say:

A. that this difference in treatment should stop now .

B. that it's better than it used to be

C. that it's worse in other countries

D. that people of color are overly sensitive .

Answers

Answer:

a

Explanation:

the others are rude, and rather support this, while a helps to support the ending of white privlige

Answer:

A. Definitely!

Explanation:

If everyone says that in other country that's worst and let it go, racism will never stop! Saying that people of color are overly sensitive is also racist because everyone can be sensitive. There color of skin change nothing! They are humans like everyone and if they want to defend themself, they have the right! Racism still exist and it needs to stop after all these years of sufferance and pain. White people are not better that people of color. Everyone deserve to be equal. Thank you.

The British gold sovereign coin is an alloy of gold and copper having a total mass of 7.988 g, and is 22-karat gold.

(a) Find the mass of gold in the sovereign in kilograms using the fact that the number of karats = 24× (mass of gold)/ total mass.

(b) Calculate the volumes of gold and copper, respectively, used to manufacture the coin.

(c) Calculate the density of the British sovereign coin.

Answers

Answer:

(a) [tex]m_{gold}=7.322g[/tex]

(b)

[tex]V_{gold}=0.379cm^3[/tex]

[tex]V_{copper}=0.122cm^3[/tex]

(c) [tex]\rho _{coin}=15.94g/cm^3[/tex]

Explanation:

Hello,

(a) In this case, with the given formula we easily compute the mass of gold contained in the sovereign  as shown below:

[tex]m_{gold}=\frac{m_{tota}*karats}{24}=\frac{7.988g*22}{24}=7.322g[/tex]

(b) Now, by knowing the density of gold and copper, 19.32 and 8.94 g/cm³ respectively, we compute each volume, by also knowing that the rest of the coin contains copper:

[tex]V_{gold}=\frac{m_{gold}}{\rho_{gold}} =\frac{7.322g}{19.32g/cm^3}=0.379cm^3[/tex]

[tex]m_{copper}=7.988g-7.322g=1.09g\\V_{copper}=\frac{m_{copper}}{\rho_{copper}}=\frac{1.09g}{8.94g/cm^3} \\\\V_{copper}=0.122cm^3[/tex]

(c) Finally, the volume is computed by dividing the total mass over the total volume containing both gold and copper:

[tex]\rho _{coin}=\frac{m_{total}}{V_{gold}+V_{copper}}=\frac{7.988 g}{0.379cm^3+0.122cm^3}\\ \\\rho _{coin}=15.94g/cm^3[/tex]

Best regards.

Answer:

a

The mass of gold is  [tex]L = 7.322 *10^{-3} \ kg[/tex]

b

     The volumes of gold and copper is  [tex]V_g = 3.794 *10^{-7} \ m^3[/tex]  , [tex]V_c = 7.426 *10^{-8} \ m^3[/tex]

c

      The density of the British sovereign coin

          [tex]\rho = 17.593*10^{3} \ kg/m^3[/tex]

Explanation:

From the question we are told that

    The total mass of the gold is  [tex]K = 7.988 \ g = 7.988 * 10^{-3} \ kg[/tex]

      The karat of the British gold sovereign is  [tex]z = 22[/tex]

     

Let the mass of gold in the alloy be  L  

Now we are told that

       [tex]z = 24 * \frac{L}{K}[/tex]

substituting value  

        [tex]22 = 24 * \frac{L}{7.988 * 10^{-3}}[/tex]

  So  [tex]L = \frac{22}{24} * 7.899*10^{-3}[/tex]

        [tex]L = 7.322 *10^{-3} \ kg[/tex]

The volume of the gold coin is  mathematically represented as

         [tex]V_g = \frac{L}{\rho_g }[/tex]

Where   [tex]\rho_g[/tex] is the density of the gold which a constant with value  

     [tex]\rho_g = 19.3 *10^{3} \ kg /m^3[/tex]

So

         [tex]V_g = \frac{7.322 *10^{-3}}{19.3 *10^{3} }[/tex]

         [tex]V_g = 3.794 *10^{-7} \ m^3[/tex]

The mass of copper is mathematically evaluated as

        [tex]m_c = K - L[/tex]

        [tex]m_c = 7.988*10^{-3} - 7.322 *10^{-3}[/tex]

        [tex]m_c = 6.657 *10^{-4} \ kg[/tex]

Volume of the copper is  

          [tex]V_c = \frac{m_c}{\rho_c}[/tex]

Where   [tex]\rho_c[/tex] is the density of the copper which a constant with value  

        [tex]\rho_c = 8.92 * 10^{3} \ kg/m^3[/tex]

So

       [tex]V_c = \frac{6.657 *10^{-4}}{8.92 *10^{3}}[/tex]

       [tex]V_c = 7.426 *10^{-8} \ m^3[/tex]

The total volume of the British gold sovereign coin is  \

        [tex]V = V_g + V_c[/tex]

substituting values

        [tex]V = 3.7939 *10^{-7} + 7.4626 *10^{-7}[/tex]

        [tex]V = 4.54 *10^{-7} \ m^3[/tex]

The density of the British gold sovereign coin is

      [tex]\rho = \frac{K}{V}[/tex]

substituting values

         [tex]\rho = \frac{7.988 *10^{-3}}{4.54 *10^{-7}}[/tex]

         [tex]\rho = 17.593*10^{3} \ kg/m^3[/tex]

What diffuses faster: a gas sample into a vacuum container, or a gas sample into an air filled container?

Answers

Answer:

A gas sample into a vacuum diffuses faster than a gas sample into an air-filled container.

Explanation:

Diffusion

When a gas is introduced into a closed space, the molecules of the gas move freely and spread throughout the closed space.

The gas molecules tend to move from higher concentration to lower concentration area so that the concentration of gas throughout the closed space comes in equilibrium. This happens because higher concentration spaces have a greater number of gas molecules and vice-versa. In other words, gas molecules move towards the spaces having less concentration, i.e., they have a smaller number of gas molecules, and hence, can accommodate additional gas molecules.

This process of dispersion of gas molecules, as a result of difference in concentration, is called diffusion. The speed of diffusion is affected by the collisions suffered by the gas molecules.

When the molecules of gas disperse in any space, they have a tendency to travel in a straight line. In this process, they hit the molecules of other gases in the same space which causes a decrease in the speed of the molecules of gas hence, slowing the process of dispersion or diffusion.

Diffusion in air-filled container

When a gas is introduced into a closed container which is already filled with air, the molecules of the newly-introduced gas, as per their tendency, tend to move throughout the closed container irrespective of the concentration gradient.

Diffusion in a vacuum container

Whereas, in vacuum, the molecules of the introduced gas do not face any collisions with any molecules of other gas. The molecules of gas move freely until they collide with the sides of the container. The only collision occurring in a vacuum container is when the molecules hit the containers. Hence, gas diffusion takes place faster in a closed container having vacuum than a closed container which is already filled with air.  

if 84.9 grams of solid iron reacts with oxygen gas, how many molecules of oxygen will react

Answers

Answer:

Molecules of oxygen [tex]= 6.86 * 10^{23}[/tex]

Explanation:

The balanced equation of reaction between iron and oxygen is  

4 Fe     +  3 O2  → 2 Fe2O3

4 moles of iron react with 3 moles of oxygen.

Mass of one mole of iron is 55.845

number of iron moles in 84.9 grams of solid iron is equal to

[tex]\frac{84.9}{55.845} \\= 1.52[/tex]

Now 1 mole of iron will react with [tex]\frac{3}{4} = 0.75[/tex] mole of oxygen

Thus 1.52 moles of iron will react with [tex]0.75 * 1.52 = 1.14[/tex] moles of oxygen

Number of atoms of oxygen in 1.14 moles

[tex]1.14* 6.02 * 10^{23}\\[/tex]

[tex]= 6.86 * 10^{23}[/tex]

We now consider three moles of ideal gas at the same initial state (3.0 L at 273 K). This time, we will first perform an isobaric compression, then an isothermal expansion to bring the gas to the final state with the same volume of 3.0 L, and at temperature 110 K. Hint (a) How much work (in J) is done on the gas during the isobaric compression? Wcompression = J (b) How much work (in J) is done on the gas during the isothermal expansion? Wexpansion = J

Answers

Answer:

Explanation:

check the image

a)

The workdone on the gas during during the isobaric compression

W = pΔV

= nRΔT

= 2 * 8.314 * (273-110)

=2710J

b) The workdone on the gas during during the isothermal expansion

[tex]W= nRT_fIn(\frac{V_f}{V_i} )\\\\2*8.314*110In\frac{110}{273} \\\\=-1662.6J[/tex]

Answer:

a) The work done during the isobaric compression is 4060.91 J.

b) The work done during the isothermal expansion is 2489.58 J.

Explanation:

a) Here we have two different processes. We calculate the work done during the isobaric compression using the following formula:

[tex] W= -P. (V₂ - V₁) [/tex]

Since the process is isobaric, the pressure is constant. First we need to find this value. In order to do that, we use the ideal gas equation:

[tex] p.V= n.R.T [/tex]

[tex] p= [n.R.T] ÷ V = [3 mol × 0.082 (L.atm÷mol.K) × 273 K] ÷ 3 L [/tex]

p = 22.39 atm

Now, we need to find V₂. We do this using Charles' law:

[tex] V₁/T₁ = V₂/T₂ [/tex]

[tex]  V₂ = V₁/T₁ × T₂ = 3 L ÷ 273 K × 110 K [/tex]

V₂ = 1.21 L

Now we are in condition to calculate the work done during the isobaric compression:

[tex] W= -P. (V₂ - V₁) [/tex]

[tex] W= -22.39 atm. (1.21 - 3) L [/tex]

W= 40. 07 L.atm

We multiply this value by 101.325 to convert it to joules: W= 4060.91 J

b) To calculate the work done during the isothermal expansion, we use the following equation:

[tex] W = n.R.T. ln (V₂/V₁) [/tex]

[tex] W = 3 mol ×0.082 (L.atm/mol.K) × 110 K × ln (3L / 1.21 L) [/tex]

W= 24.57 L.atm

We convert this value to joules: W= 2489.58 J

A barrel of water weighs 60 pounds. What must you put in it for it to weigh 40 pounds?

Answers

Answer:

A hole

Explanation:

put a hole in the barrel and let some water out

The thing you would add to the barrel would be holes which would cause water to fall out of the barrel.

What is a pound?

Pound is defined as the basic unit for weight in the Foot Pound Second (F.P.S) system and is equal to 16 ounces.

An example of a pound is a man weighing 186 pounds.

The thing you would add to the barrel would be holes which would cause water to fall out of the barrel.

The amount of holes you would add and where you would add them would depend all on how much the barrel weighs without the water.

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Question 1 When of alanine are dissolved in of a certain mystery liquid , the freezing point of the solution is lower than the freezing point of pure . On the other hand, when of iron(III) chloride are dissolved in the same mass of , the freezing point of the solution is lower than the freezing point of pure . Calculate the van't Hoff factor for iron(III) chloride in . Be sure your answer has a unit symbol, if necessary, and round your answer to significant digits.

Answers

Answer:

See explaination

Explanation:

please kindly see attachment for the step by step solution of the given problem

In a solution at 25 degrees Celsius the H is 3.5 x 10^-6 M. What is the OH

Answers

Answer:

Explanation:

 [ H⁺] = 3.5 x 10⁻⁶ M .

[ H⁺] [ OH⁻] = 10⁻¹⁴

[ OH⁻] x 3.5 x 10⁻⁶ = 10⁻¹⁴

[ OH⁻] = 2.857 x 10⁻⁹ M .

CHEM EXPERT NEEDED***
A volume of 150.0 mL of H2O is initially at 24.00 °C. A chilled steel rod at 2.50 °C is placed in the water and the final temperature of the system is 21.20 °C.

Specific heat of water = 4.184 J/(g⋅∘C) and the specific heat of steel = 0.452 J/(g⋅∘C)

Write the equation and calculate the mass of the rod.

Answers

Answer:

1. m₁C₁ΔT₁ + m₂C₂ΔT₂ = 0

2. 207 g

Explanation:

This is a problem in calorimetry — the measurement of the quantities of heat that flow from one object to another.

It is based on the Law of Conservation of Energy — Energy can be transformed from one type to another, but it cannot be destroyed or created.

If heat flows out of one object, the same amount of heat must flow into another object.

Since there is no change in total energy,

Heat₁ + heat₂ + heat₃+ … = 0

The symbol for the quantity of heat transferred is q, so we can rewrite the word equation as

q₁ + q₂ + q₃ + … = 0

The formula for the heat absorbed or released by an object is

 q = mCΔT, where

m = the mass of the sample

C = the specific heat capacity of the sample, and

ΔT = T_f - T_i = the change in temperature

1. Equation

There are two heat flows in this problem,

Heat from steel rod + heat absorbed by water = 0

               q₁               +                  q₂                    = 0

           m₁C₁ΔT₁           +            m₂C₂ΔT₂             = 0

2. Data:

m₁ = ?;               C₁ = 0.452 J°C⁻¹g⁻¹;T_f = 21.20 °C; T_i =   2.50 °C

V₂ = 150.0 mL; C₂ = 4.184 J°C⁻¹g⁻¹; T_f = 21.20 °C; T_i = 24.00 °C

3. Calculations

(a) m₂

The density of water is 0.9982 g/mL, so  

m₂ = 150.0 mL × 0.9982 g/mL = 149.7 g

(b) Temperature changes  

[tex]\Delta T_{1} = T_{\text{f}} - T_{\text{i}} = 21.20 \, ^{\circ}\text{C} - 2.50 \, ^{\circ}\text{C} = 18.70 \, ^{\circ}\text{C}\\\Delta T_{2} = T_{\text{f}} - T_{\text{i}} = 21.20 \, ^{\circ}\text{C} - 24.00 \, ^{\circ}\text{C} = -2.80 \, ^{\circ}\text{C}[/tex]

(c) q₁

q₁ = m₁C₁ΔT₁ = m₁ × 0.452 J°C⁻¹g⁻¹ × 18.70 °C = 8.452m₁ J·g⁻¹

(d) q₂

q₂ = m₂C₂ΔT₂ = 149.7 g × 4.184 J°C⁻¹g⁻¹ × (-2.80 °C) = -1754 J

(e) m₁

[tex]\begin{array}{rcl}q_{1} + q_{2} & = & 0\\8.452m_{1} \, \text{J}\cdot\text{g}^{-1} + (-\text{1754 J}) & = & 0\\8.452m_{1}\,\text{g}^{-1} - 1764 &=& 0\\m_{1} & = & \dfrac{1764}{8.452 \,\text{g}^{-1}}\\\\ & = & \textbf{207 g}\\\end{array}\\\text{ The mass of the steel rod is $\large \boxed{\textbf{207 g}}$}[/tex]

Use the periodic table to correctly describe the arrangement of electrons in an oxygen atom. Check all of the
boxes that apply.

Answers

Answer:

second option and last option

Explanation:

Know how to do an electron configuration. This is correct because it adds up to 8 and is in the correct order.

All valence electrons are in the last shell. In this case, 2p is the last shell.

Answer:

It's the second and the second to last

Explanation:

At which electrade in a voltaic cell does redaction always occar?​

Answers

Answer:cathode

Explanation:It is also known as the galvanic cell or electrochemical cell. In the voltaic cell, the oxidation occurs at an anode which is a negative electrode and the reduction occurs at the cathode which is a positive electrode.

Which of the following atoms is the smallest?

Be

Ne

O

Li

B

Answers

Answer:

Li

Explanation:

The element, Neon (Ne), is the smallest among the given elements

From the question,

We are to determine which of the given elements is the smallest.

The given elements are

Be - Beryllium  

Ne - Neon  

O - Oxygen

Li - Lithium

B - Boron

From the periodic table, we can observe that all of the given elements belong to period 2.

Using the trend of atomic size on the periodic table,

We know that, atomic size decreases across the period.

This means, the atomic sizes of the elements will decrease in the order

Li > Be > B > O > Ne

Hence, the element, Neon (Ne), is the smallest among the given elements

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The number of atoms in exactly 12 grams of carbon-12 is called

Answers

is this for mathh? and can u explain more

The number of atoms which are present exactly in 12 grams of carbon-12 is called Avogadro's number.

What is Avogadro's number?

Avogadro's number is the number of atoms which are present in 1 mole of any substance and it is equal to 6.022×10²³.

And moles will be calculated as:

n = W/M, whereW = given massM = molar mass

Moles of Carbon-12 = 12g / 12g/mol = 1mole

In 1 mole of Carbon-12 = 6.022×10²³ atoms are present.

Hence, the number of atoms in exactly 12 grams of carbon-12 is called Avogadro's number.

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What is the molarity of a solution containing 0.05 moles of solute in 0.25L of solution?

Answers

Answer:

  0.2 M

Explanation:

The molarity is the number of moles per liter:

  (0.05 moles)/(0.25 liter) = 0.2 moles/liter = 0.2 M

HURRRYYYY
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:

()CaSO4 → ()O2 + ()CAS

Answers

Answer:

1, 2, 1

Explanation:

Please see the step-by-step solution in the picture attached below.

Hope this answer can help you. Have a nice day!

Answer:

1,2,1

Explanation:

just did the assigment

Complete the table:
Mass Solute Mass Solvent Mass Solution Mass Percent
2.65 g 26.0 g _____ _____
_____ 46.8 g _____ 4.0 %
1.68 g _____ 26.2 g _____
26.7 g _____ _____ 5.9 %

Answers

Answer:

1.

Mass solution = 28.65 g

Mass percent = 9.14 %

2.

Mass solute = 1.95 g

Mass solution = 48.75 g

3.

Mass solvent = 24.52 g

Mass percent = 6.41 %

4.

Mass solution = 476.8 g

Mass solvent =450.1 g

Explanation:

Hello,

In this case, we define the mass percent as:

[tex]\%m/m=\frac{m_{solute}}{m_{solute}+m_{solution}} *100\%[/tex]

Wherein we use the mass of the solute and the mass of the solvent in order to compute it, thus, for each case we have:

1.

Mass solution: 2.65 g + 26.0 g = 28.65 g

Mass percent: 2.62 g / (2.65 g + 26.0 g) x 100% = 9.14 %

2.

Mass solute: 4.0 % x 46.8 g / (1 - 4.0 %) = 1.95 g

Mass solution: 1.95 g + 46.8 g = 48.75 g

3.

Mass solvent: 26.2 g - 1.68 g = 24.52 g

Mass percent: 1.68 g / (1.68 g + 24.52 g) x 100% = 6.41 %

4.

Mass solution: 26.7 g / 5.6 % = 476.8 g

Mass solvent: 476.8 g - 26.7 g =450.1 g

Best regards.

Answer:

20.9

Explanation:

Among nonmetals,which nonmetal is most likely to form a covalent bond?

Answers

Answer:

most common non metal is chlorine

Base your answers on the graph below, which represents uniform cooling of a sample of a pure substance, starting as a gas. The boiling point of the substance is

Answers

Answer:

120

Explanation:

Because it starts as gas at from A to B, B to C is gas and liquid equilibrium, so in order to go to boiling point (point where it goes from liquid to gas) it happens at 120 because after that you see that steep slope which represents the gas being formed.

The transition from liquid to gas, or the boiling point, occurs at 120 because after that you see that steep slope, which symbolizes the gas being formed. This is because the transition from liquid to gas, or the boiling point, occurs at 120 because it starts as a gas at A to B, B to C is gas and liquid equilibrium.

What is boiling point ?

The temperature at which a liquid's vapor pressure equals the pressure around it and the liquid transforms into a vapor is known as the boiling point of a material. A liquid's boiling point changes according on the atmospheric pressure in the area.

A cooling curve is a line graph that depicts the transition of matter from one phase to another, usually from a liquid or gas to a solid. Time is an independent variable (X-axis), while temperature is a dependent variable (Y-axis).

Thus, the boiling point of the substance is 120° c.

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Some building materials contain small capsules filled with paraffin wax to improve the insulating properties of the materials. The melting and freezing of paraffin inside the capsules in the material helps to regulate temperature. Paraffin wax begins to melt at 37°C37°C.(a) While the wax is melting, is the net flow of thermal energy from the wax to the surroundings or from the surroundings to the wax? Justify your answer.(b) Calculate the amount of thermal energy, in kJkJ, that is required to melt 15.215.2 grams of solid paraffin wax when the temperature of the surroundings is above the melting point of paraffin. (The molar mass of paraffin is 282.62g/mol282.62g/mol, and its molar heat of fusion is 48.78kJ/mol)(c) When paraffin wax melts, its density decreases. Provide a particle-level explanation of this observation.

Answers

Answer:

(a)

From surrounding to wax

(b)

Q = 2.62 KJ

(c)

Density of a substance is defined as the no. of particles of the substance, that occur in a unit volume. So, when the substance melts, the inter-molecular attractive forces and bonds between molecules or atoms are weakened. This, increases the distance between the molecules or atoms. Hence, the no. of particles in a unit volume is decreased. As, a result of this, the density of the substance also decreases.

Explanation:

(a)

During the melting process, the solid material or substance requires energy, in order to break the bonds between its molecules or atoms.

Therefore, while the wax is melting, the net flow of thermal energy is from surrounding to the wax.

(b)

The amount of energy required to melt solid paraffin wax is given by the formula:

Q = nC

where,

Q = amount of energy

C = Molar Heat of Fusion = 48.78 KJ/mol

n = No. of Moles = Mass in gram/Molar Mass = (15.2 g)/(282.62 g/mol)

n = 0.0538 mol

Therefore,

Q = (0.0538 mol)(48.78 KJ/mol)

Q = 2.62 KJ

(c)

Density of a substance is defined as the no. of particles of the substance, that occur in a unit volume. So, when the substance melts, the inter-molecular attractive forces and bonds between molecules or atoms are weakened. This, increases the distance between the molecules or atoms. Hence, the no. of particles in a unit volume is decreased. As, a result of this, the density of the substance also decreases.

(a) During the melting of wax, the flow of thermal energy has been from the surroundings to the wax.

(b) The amount of heat requires for the melting of 15.215 grams of solid paraffin has been 2.62 kJ.

(c) The density decreases due to a decrease in the number of molecules per unit volume.

(a) Melting results in the conversion of solid-state to the liquid state. This step requires energy. Thus, the flow of energy has been from the surroundings to the wax.

(b) Amount of heat requires (Q) can be given by:

Q = nC

Where, n = moles of the sample, and C = heat of fusion

Moles of paraffin = [tex]\rm \dfrac{weight}{molecular\;weight}[/tex]

Moles of paraffin = [tex]\rm \dfrac{15.215}{286.62}[/tex]

Moles of paraffin = 0.0538 moles

Q = 0.0538 [tex]\times[/tex] 48.78 kJ/mol

Q = 2.62 kJ.

The amount of heat requires for the melting of 15.215 grams of solid paraffin has been 2.62 kJ.

(c) The density has been the mass or number of particles present per unit volume. The melting of wax results in a weaker intermolecular force. The resulting liquid will have fewer molecules present in the unit volume.

Thus, the density decreases due to a decrease in the number of molecules per unit volume.

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where does the chemical reaction take during photosynthesis ​

Answers

Answer:

in all green plants and most algae

Balance the equation below, using the smallest whole-number coefficients. ____Fe(s) + ____ O2(g) + ____ H2O(l) → ____Fe(OH)2(s)

Answers

Answer:

2Fe(s) + O₂(g) + 2H₂O(l) → 2Fe(OH)₂(s)

Explanation:

Balanced equation willl be:

[tex]2Fe(s) + O_2(g) + 2H_2O(l) - > 2Fe(OH)_2[/tex]

What is balance equation with example?

A balanced chemical equation occurs when the number of the atoms involved in the reactants side is equal to the number of atoms in the products side. In this chemical reaction, nitrogen (N2) reacts with hydrogen (H) to produce ammonia (NH3). The reactants are nitrogen and hydrogen, and the product is ammonia.

What is the rule of balance?

On a separate sheet of paper, make a claim in which you mathematically state the rule of balance - that is, the rule that one must use to determine if two weights placed on opposite sides of the fulcrum will balance each other.

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How could weathering by release of pressure affect the amount of weathering by freezing and thawing?

Answers

When the water in the cracks freezes, it expands by 9 to 10 percent, exerting pressure on the rock, according to BBC Bitesize. This action can widen the cracks in the rock, and when the temperature rises above freezing, the ice thaws, allowing the water to seep further into the cracks.

The amount of weathering by the freezing and thawing process of water is the most effective weathering.

What is weathering?

Weathering is a process in which breaking or dissolving of rocks and minerals present on the earth surface.

Freezing and thawing weathering is a kind of physical weathering in which water goes down to the pores of rock and gets freeze and expands and causes breaking of rocks.Release of pressure also result in the weathering of the underlying rocks.

Weathering by the freezing effect of water causes more effect on the breaking as compare to the pressure release weathering.

Hence Freezing & thawing weathering is most powerful weathering.

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