A student is determining the density of an unknown metal with a mass of 32.56 g. The student partially fills a graduated cylinder with water and measures the volume of the water by itself as 14.78 mL. The student then adds the metal to the water and measures the new volume as 20.44 mL. What is the identity of the metal

Answer:

B, 2.22×10^22 molecules

Explanation:

Given PV=nRT, n=PV/RT

n=103.7×1.0/8.314×(65+273.15)

= 0.0368858... moles

Given n= number of particles/avogadros number

number of particles=n×avogadros number

number of particles = 0.03688...×6.02x10^23

= 2.22×10^22 molecules

The enthalpy change of the reaction C(diamond) → C(graphite) is -2.9 kJ.

The given information is ΔHrxn for the reaction C(diamond) → C(graphite) can be calculated with the given equations:Equations:  C(diamond) + O2(g) → CO2(g) ΔH = −395.4 kJ  2 CO2(g) → 2 CO(g) + O2(g) ΔH = 566.0 kJ  C(graphite) + O2(g) → CO2(g) ΔH = −393.5 kJ  2 CO(g) → C(graphite) + CO2(g) ΔH = −172.5 kJThe required reaction can be obtained by adding the equations (1) and (4), as follows:C(diamond) + O2(g) + 2CO(g) → C(graphite) + 3CO2(g)Addition of the two equations (1) and (4) results in a reaction whose products are C(graphite) and CO2.

To get the final equation that involves only the required reactants and products, the equation (2) should be added, which consumes CO2 and produces O2, as shown below:C(diamond) + O2(g) → CO2(g)  ΔH = −395.4 kJ [eq. (1)]  2 CO(g) → C(graphite) + CO2(g)  ΔH = −172.5 kJ [eq. (4)]  2 CO2(g) → 2 CO(g) + O2(g)  ΔH = 566.0 kJ [eq. (2)]  C(diamond) + O2(g) + 2CO(g) → C(graphite) + 3CO2(g)  ΔHrxn=ΣΔHf(products)−ΣΔHf(reactants)  ΔHrxn=[(3 mol CO2)(-393.5 kJ/mol) + (1 mol C(graphite))(0 kJ/mol)] − [(1 mol C(diamond))(0 kJ/mol) + (1 mol O2)(0 kJ/mol) + (2 mol CO(g))(−172.5 kJ/mol)] − [(2 mol CO2)(566.0 kJ/mol)]  ΔHrxn=−2.9 kJ.

for such more questions on reaction

https://brainly.com/question/11231920

#SPJ8

We need to add 68.8 mL of the 2.00 M stock solution of KCl to a 0.250 L volumetric flask and then add enough water to reach the 0.250 L mark to prepare a 0.550 M solution of KCl.

We can use the dilution equation to calculate the volume of the 2.00 M stock solution of KCl needed to prepare the 0.550 M solution:

M1V1 = M2V2

where M1 is the initial concentration of the stock solution, V1 is the volume of the stock solution added, M2 is the final concentration of the diluted solution, and V2 is the final volume of the diluted solution.

We know that M1 = 2.00 M, M2 = 0.550 M, and V2 = 0.250 L. Substituting these values into the dilution equation, we can solve for V1:

(2.00 M)(V1) = (0.550 M)(0.250 L)

V1 = (0.550 M)(0.250 L) / (2.00 M)

V1 = 0.0688 L

We need to convert the volume to milliliters (mL):

V1 = 68.8 mL

For more question on stock solution click on

https://brainly.com/question/24697661

#SPJ11

Answer:

D Cobalt

Explanation:

The volume of the sphere is  40 -25 = 15 cm^3

Density = mass/volume = 133 gm / 15 cm^3 = 8.87 gm/cm^3

  which corresponds to Cobalt from the chart

250 L of 5.0% w/v glucose solution can be prepared using 125 g of glucose.

w/v = [ mass of solute (g) / volume of solution (mL) ] × 100

5.0 % w/v = [ 125 g / volume of solution (mL) ] × 100

volume of solution (mL) = [ 125 g / 5.0 % w/v ] x 100

volume of solution (mL) = [ 125 g / (5.0 / 100) ] x 100

volume of solution (mL) = [ 125 g / 0.05 ] x 100

The bulk density at 20 percent moisture, given that the soil dries to 20 percent by weight is 1.4 g/cm³

First, we shall obtain the initial volume of the soil. Details below:

Volume = mass / density

Initial volume of soil = 100 / 1.3

Initial volume of soil = 76.93 cm³

Next, we shall obtain the volume after the soil dries to 20 percent by weight. Details below:

We were told that the soil shrinks by an amount equal to the water loss, thus we have

Initial mass of water = 40% = 40 g

Water lost = 20% = 20 g

New mass of water = 40 - 20 = 20 g

Thus,

Volume = Equal value of mass of water lost = 20 cm³

Finally, we shall obtain the bulk density at 20 percent moisture. Details below:

Bulk density at 20 percent moisture = Total mass / new volume

Bulk density at 20 percent moisture = 80 /  5.93

Bulk density at 20 percent moisture = 1.4 g/cm³

Learn more about bulk density:

https://brainly.com/question/32032726

#SPJ1

Answer:

Mass = 15.13 g

Explanation:

Given data:

Mass of ammonia formed = ?

Number of hydrogen atoms = 8.11× 10²³ atoms

Solution:

Chemical equation:

N₂ + 3H₂     →      2NH₃

1 mole = 6.022× 10²³ atoms

8.11× 10²³ atoms × 1 mol / 6.022× 10²³ atoms

1.35 moles of hydrogen

Now we will compare the moles of hydrogen and ammonia,

              H₂         :        NH₃

               3          :          2

              1.35      :         2/3×1.35 = 0.89

Mass of ammonia:

Mass = number of moles × molar mass

Mass = 0.89 mol × 17 g/mol

Mass = 15.13 g

Answer:  Soundwaves travel as longitudinal or transverse waves depending on the temperature of the medium.

Explanation: i think its C

When fossil fuels burn, several forms of energy are produced, including:

Heat energy: The primary form of energy released during fossil fuel combustion is heat. Fossil fuels contain chemical energy stored for millions of years, and when they burn, this energy is released in the form of heat. The heat energy can be harnessed for various purposes, such as heating buildings or generating steam to drive turbines.

Light energy: Burning fossil fuels can also produce light energy in the form of flames or glowing embers. This light energy is a byproduct of combustion.

Mechanical energy: Heat generated by burning fossil fuels can be converted into mechanical energy. This is typically achieved by using heat to produce steam, which drives a turbine connected to a generator. The rotating turbine converts the heat energy into mechanical energy, which is further transformed into electrical energy.

Electrical energy: Through the process described above, burning fossil fuels can ultimately generate electrical energy. The mechanical energy produced by the turbine is converted into electrical energy by the generator. Electrical energy can power various devices, appliances, industries, and infrastructure.

It's critical to note that while burning fossil fuels can produce useful forms of energy, it also results in the release of carbon dioxide and other greenhouse gases. This contributes to climate change and environmental concerns. As a result, there is a global shift towards cleaner and renewable energy sources to mitigate these negative impacts.

The pH of added acid at 40 mL is 1.87.

Given,

Concentration of pyridine = 0.125 M

Concentration of HCl = 0.1 M

Volume of pyridine = 25 mL

The millimoles of HCl is calculated as follows:

mmol of HCl = Molarity × Volume of HCl

                     = 0.1 M × 40 mL

                     = 4 mmol

The millimoles of pyridine is calculated as follows:

mmol of pyridine = Molarity × Volume of HCl

                            = 0.125 M × 25 mL

                            = 3.125 mmol

The concentration of excess HCl is calculated as follows:

Concentration of excess HCl = Millimoles / Total volume

                                                = (4.0 - 3.125) mmol / (40 + 25) mL

                                                = 0.0135 M

The pH of added acid is calculated as shown below:

pH = - log [H⁺]

     = - log (0.0135)

     = 1.87

Hence, the pH of added acid is 1.87.

Learn more about pH from the link given below.

https://brainly.com/question/16232412

#SPJ1

Answer:

a.In the garden

Explanation:

Because, inside from garden with big tub like a stock tank on your patio. They grow tubers planted in pots beneath the water and send up stems with rounded leaves and star-shaped blossoms that float on the surface.

I hope it helps to us. Always welcome my youngest sister:). keep learning and God bless.

Answer:

the heat capacity of steam is 2.01 J/(g⋅∘C) and of ice is 2.09 J/(g⋅∘C). 1. See answer.

The specific heat capacity of the alloy is 0.120 J/g°C.

What is Specific heat capacity?

Specific heat capacity, also known as specific heat, is the amount of heat required to raise the temperature of a unit mass (usually one gram) of a substance by one degree Celsius or Kelvin. Each substance has its own specific heat capacity, which depends on its chemical composition and physical state. The SI unit of specific heat is joules per gram per degree Celsius (J/g°C).

First, we need to calculate the heat absorbed by the water:

q_water = m_water * C_water * ∆T

where m_water is the mass of water, C_water is the specific heat capacity of water, and ∆T is the change in temperature of the water.

m_water = 50.0 g

C_water = 4.18 J/g°C

∆T = 31.10°C - 22.00°C = 9.10°C

q_water = (50.0 g) * (4.18 J/g°C) * (9.10°C) = 1911.5 J

Next, we need to calculate the heat released by the alloy:

q_alloy = - q_water

Since the calorimeter is insulated, the heat lost by the alloy is equal to the heat gained by the water.

q_alloy = m_alloy * C_alloy * ∆T

where m_alloy is the mass of the alloy, C_alloy is the specific heat capacity of the alloy, and ∆T is the change in temperature of the alloy.

m_alloy = 29.3 g

∆T = 31.10°C - 93.00°C = -61.90°C (note the negative sign)

q_alloy = (29.3 g) * C_alloy * (-61.90°C)

Finally, we can solve for the specific heat capacity of the alloy:

C_alloy = - q_water / (m_alloy * ∆T)

C_alloy = - (1911.5 J) / ((29.3 g) * (-61.90°C))

C_alloy = 0.120 J/g°C

Therefore, the specific heat capacity of the alloy is 0.120 J/g°C.

Learn more about Specific heat capacity from given link

https://brainly.com/question/27991746

#SPJ1

Answer:

The answer is solar cell.

Explanation:

It’s the smallest of the 4 choices, the smaller it is the less it wastes.

Answer:

Explanation:

solar cell

The percent composition of CuBr₂ is approximately 28.46% of Cu and 71.54% of Br.

To determine the percent composition of CuBr₂ (copper(II) bromide), we need to calculate the mass of each element in the compound and then divide it by the molar mass of the entire compound.

The molar mass of CuBr₂ can be calculated by adding up the atomic masses of copper (Cu) and bromine (Br) in the compound. The atomic masses of Cu and Br are approximately 63.55 g/mol and 79.90 g/mol, respectively.

Molar mass of CuBr₂ = (63.55 g/mol) + 2(79.90 g/mol) = 223.35 g/mol

Now, let's calculate the percent composition of each element in CuBr₂:

Percent composition of copper (Cu):

Mass of Cu = (63.55 g/mol) / 223.35 g/mol × 100% ≈ 28.46%

Percent composition of bromine (Br):

Mass of Br = 2(79.90 g/mol) / 223.35 g/mol × 100% ≈ 71.54%

Therefore, the percent composition of CuBr₂ is approximately:

- Copper (Cu): 28.46%

- Bromine (Br): 71.54%

These values represent the relative mass percentages of copper and bromine in the compound CuBr₂.

for more such questions on composition

https://brainly.com/question/28250237

#SPJ8

Answer:

E = hV

Explanation:

Hello,

Photo electric effect theory was borne out the the confusing if light was either a particle or a wave. However Albert Einstein came up with a theory that light was a particle and each particle carry a certain amount of energy referred to as photons.

He used Max Planck's idea and theorized that since light is made up of photon, when each photon comes in contact with the surface of a metal, the energy is transferred to the electron.

E = hv

E = energy of the photons

h = Planck's constant = 6.626×10⁻³⁴Js

v = frequency of the photon in Hz

Answer:

B

Explanation:

Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

\(volume = \frac{mass}{density} \\\)

From the question we have

mass = 45.6 g

density = 2.9 g/cm³

\(volume = \frac{45.6}{2.9} \\ = 15.724137\)

We have the final answer as

Hope this helps you

The statement which interpret the object motion is the object moves with a constant positive velocity and then stops moving. The slope represents velocity. Therefore, option B is correct.

The term velocity is defined as vector expression representing the change in position over time of an object or particle. It is also known as speed.The unit of velocity magnitude is the meter per second (m/s).

A positive velocity merely indicates that an object is moving in the coordinate system's positive direction, whereas a negative velocity denotes that the item is going in the opposite direction.

Thus, option B is correct.

To learn more about the velocity, follow the link;

https://brainly.com/question/18084516

#SPJ1

Answer:

metallic bonding

Explanation:

Copper wire consists of Cu nuclei (that are positively charged due to the positively charged protons) that are surrounded by a "sea" of delocalized electrons (that are negatively charged that move freely throughout the material which is known as metallic bonding.

Answer:

Metallic bonding.

Explanation:

Pure copper is neither covalent nor ironic. It is a bonding called metallic bonding.

The amount, in kJ, of heat needed to completely vaporize 50.0g of water at 100°C is 118.8 kJ.

The heat needed to completely vaporize 50.0g of water at 100°C can be calculated using the following formula:

q = m x Hv

where:

First, we need to convert 50.0g to moles by dividing by the molar mass of water which is approximately 18.015 g/mol3:

moles of water = 50.0 g / 18.015 g/mol moles of water = 2.776 mol

Thus:

q = (2.776 mol) x (40.65 kJ/mol) q = 112.8 kJ

In other words, 112.8 kJ of heat is needed to completely vaporize 50.0g of water at 100°C.

More on heat of vaporization can be found here: https://brainly.com/question/12625048

#SPJ1

Answer:

Explanation:

Structural Levels of the body:
a. Characteristics of Living Things: Living things exhibit certain characteristics such as the ability to grow, reproduce, respond to stimuli, and maintain homeostasis.
b. Cell Specialization: Cells in the body are specialized to perform different functions such as muscle cells for movement, nerve cells for communication, and red blood cells for carrying oxygen.

Skeletal and Muscular System:
a. The Skeletal System: The skeletal system provides support, protection, and movement for the body. It is composed of bones, cartilage, and ligaments.
b. The Muscular System: The muscular system allows movement of the body and helps in maintaining posture. It is composed of muscles, tendons, and ligaments.

Food and Nutrition:
a. Food Pyramid: The food pyramid is a guide for healthy eating that emphasizes the importance of a balanced diet including fruits, vegetables, grains, protein, and dairy.

Digestive System:
a. Enzymes: Enzymes are proteins that help in breaking down food into simpler forms for absorption in the body. They are produced by different organs in the digestive system such as the pancreas, stomach, and small intestine.

Circulatory System:
a. Circulation: The circulatory system is responsible for the transport of blood and nutrients throughout the body. It consists of the heart, blood vessels, and blood.
b. Heart: The heart is a muscular organ that pumps blood to different parts of the body.
c. Blood Vessels: Blood vessels include arteries, veins, and capillaries that transport blood to and from the heart.

Respiratory System:
a. Respiration: Respiration is the process of inhaling oxygen and exhaling carbon dioxide. The respiratory system is responsible for this process and includes the nose, trachea, bronchi, and lungs.

Answer:

awdaef

Explanation:

Answer:

Division by zero is undefined because there is no other number to divide it by.

Explanation:

Unlike 2/2, 2/0 doesn't have anything to divide the 2 by which makes it undefined and impossible to solve.

The division by zero is undefined​, because whatever response we may give, we will then have to concur that the answer times 0 = 1, which is illogical because anything multiplied by zero is zero.

Since any attempt at definition results in a contradiction, the outcome of a division by zero cannot be defined. a=r*b. r*0=a. (1) (1) But because r*0=0 for all r, there is no solution to the equation unless a=0 (1).

Again, mathematicians have left zero divided by zero as an open problem because they are both equally valid and, to be honest, neither of them is consistent with the rest of mathematics.

Mathematically, it is impossible to divide a number by zero, just as in this illustration. Or, at the very least, there isn't currently a means to do that. Numerous attempts have been made to figure out how to divide by zero, as mathematicians are constantly looking for solutions to intriguing mathematical issues.

Thus, The division by zero is undefined​, because whatever response we may give, we will then have to concur that the answer times 0 = 1.

To learn more about division by zero is undefined, follow the link;

https://brainly.com/question/11523699

#SPJ2

Answer:

1.533 moles Au

Explanation:

To find the moles from atoms, you just use Avogadro's number (6.02214076×10^23 mol^-1) and divide by it. Hope this helped!

Answer:

\(\boxed {\boxed {\sf 1.53 \ mol \ Au}}\)

Explanation:

We are asked to find how many moles of gold are in 9.23 *10²³ atoms of gold.

Avogadro's Number or 6.022 *10²³ is used to convert atoms to moles. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are atoms of gold.

We convert using dimensional analysis. Set up a conversion factor using Avogadro's Number.

\(\frac {6.022 \times 10^{23} \ atoms \ Au}{ 1 \ mol \ Au}\)

We are converting 9.23 * 10²³ atoms of gold to moles, so we multiply by this value.

\(9.23 \times 10^{23} \ atoms \ Au *\frac {6.022 \times 10^{23} \ atoms \ Au}{ 1 \ mol \ Au}\)

Flip the conversion factor so the units of atoms of gold cancel.

\(9.23 \times 10^{23} \ atoms \ Au *\frac { 1 \ mol \ Au}{6.022 \times 10^{23} \ atoms \ Au}\)

\(9.23 \times 10^{23} *\frac { 1 \ mol \ Au}{6.022 \times 10^{23}}\)

\(\frac {9.23 \times 10^{23} }{6.022 \times 10^{23} } \ mol \ Au\)

\(1.53271338426 \ mol \ Au\)

The original measurement of atoms has 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 2 in the thousandth place tells us to leave the 3.

\(1.53 \ mol \ Au\)

9.23 *10²³ atoms of gold is equal to approximately 1.53 moles of gold.

The heat change or enthalpy change, ΔH°rxn, for the slow reaction of zinc with water is +417.7 kJ/mol.

The heat change or enthalpy change, ΔH°rxn, for the reaction of zinc (Zn) with water (H₂O) can be calculated using the standard enthalpies of formation for each species involved in the reaction.

Balanced chemical equation for the reaction is;

Zn(s) + 2H₂O(l) → Zn²⁺(aq) + H₂(g)

The standard enthalpy change for the reaction, ΔH°rxn, can be calculated as the sum of the standard enthalpies of formation of the products minus the sum of the standard enthalpies of formation of the reactants, each multiplied by their respective stoichiometric coefficients;

ΔH°rxn = Σ(nΔH°f, products) - Σ(mΔH°f, reactants)

where n and m are the stoichiometric coefficients of the products and reactants, respectively, and ΔH°f is the standard enthalpy of formation.

Assuming standard conditions (25°C and 1 atm), the standard enthalpies of formation for Zn²⁺(aq) and H₂(g) are typically tabulated values. Let's assume their values to be ΔH°f(Zn²⁺(aq)) = -153.9 kJ/mol and ΔH°f(H₂(g)) = 0 kJ/mol, respectively.

The standard enthalpy of formation of water (H₂O) is -285.8 kJ/mol.

Put the values into the equation, we get;

ΔH°rxn = [ΔH°f(Zn²⁺(aq)) + ΔH°f(H₂(g)] - [ΔH°f(Zn(s)) + 2ΔH°f(H₂O(l))]

ΔH°rxn = [-153.9 + 0] - [0 + 2(-285.8)]

ΔH°rxn = -153.9 + 571.6

ΔH°rxn = 417.7 kJ/mol

To know more about heat change here

https://brainly.com/question/18912282

#SPJ1

Density differences caused by temperature and salinity variations are fundamental drivers of ocean currents of seawater . Warm currents transport heat from the equator to higher latitudes, while cold currents transport cold water from higher latitudes to lower latitudes.

When seawater is heated, it expands and becomes less dense, causing it to rise. Conversely, when seawater cools, it contracts and becomes denser, causing it to sink. These density differences due to temperature variations create vertical movements in the ocean known as thermohaline circulation or convection currents. On the other hand, regions with high freshwater input from rivers or heavy precipitation have lower salinity, resulting in lower density. This lighter water tends to float on the denser seawater beneath it, leading to the formation of surface currents that transport water from areas of low salinity to areas of higher salinity. These ocean currents play a vital role in shaping global climate patterns and maintaining the balance of heat and nutrients in the ocean ecosystem.

Learn more about the ocean current here.

https://brainly.com/question/21654036

#SPJ1