What is the law of multiple proportions?
A. The proportion of elements to compounds is constant.
B. All elements are found in equal proportions in nature.
C. Different compounds may contain the same elements but may have different ratios of those elements.
D. All compounds contain the same elements in the same proportions.

Explanation:

here is the answer to your question.

Answer:

The initial temperature of the brass sample is 90.1°C

Note: The question is incomplete. A similar but complete question is given below :

A 52.9g sample of brass, which has a specific heat capacity of 0.375·J·g−1°C−1, is put into a calorimeter (see sketch at right) that contains 100.0g of water. The temperature of the water starts off at 15.0°C. When the temperature of the water stops changing it's 18.4°C. The pressure remains constant at 1 atm. Calculate the initial temperature of the brass sample. Be sure your answer is rounded to 2 significant digits.

Explanation:

Assuming that the calorimeter is an isolated system and that no heat is lost from the calorimeter. The total heat in the system is the sum of the heat content of the brass and that of water

Total heat lost by the brass = heat gained by the water

The quantity of heat lost or gained, Q = mcΔT

Where m = mass of the substance, c = specific heat capacity of substance, ΔT = temperature change

Heat gained by water is positive while heat lost by brass is negative

mass of brass = 52.9 g, specific heat capacity of brass = 0.375·J·g−1°C−1, ΔT = (18.4 - t °C; where t is the initial temperature), mass of water = 100.0 g, specific heat capacity of water = 4.186 J/g°C, ΔT = = 18.4 - 15.0 = 3.4 °C

Heat lost by brass z= - [ 52.9 × 0.375 × (18.4 - t)] = -365.01 + 19.8375t

Heat gained by water = 100 × 4.186 × 3.4 = 1423.24

Equating heat lost by brass to heat gained by water

-365.01 + 19.8375t = 1423.24

19.8375t = 1423.24 + 365.01

19.8375t = 1788.25

t = 90.1° C

Therefore, the initial temperature of the brass sample is 90.1°C

Answer:

True

Explanation:

A hypothesis can be proven true through experimentation. For example, if you hypothesize that a balloon with helium will float in the air, and then you test this and the balloon floats, you have just proven that your original hypothesis is true.

Answer: The molarity of an HCl solution is 0.218 M if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid.

Explanation:

Given: [tex]V_{1}[/tex] = 43.6 mL,      [tex]M_{1}[/tex] = 0.125 M

[tex]V_{2}[/tex] = 25.0 mL,        [tex]M_{2}[/tex] = ?

Formula used to calculate the concentration of acid is as follows.

[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]

Substitute the values into above formula.

[tex]M_{1}V_{1} = M_{2}V_{2}\\0.125 M \times 43.6 mL = M_{2} \times 25.0 mL\\M_{2} = 0.218 M[/tex]

Thus, we can conclude that the molarity of an HCl solution is 0.218 M if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid.

The molarity of the HCl solution used in the neutralization reaction has been 0.218 M.

The reaction of NaOH with HCl has been a neutralization reaction. The resultant will be salt and water.

In the reaction the molarity can be calculated as:

Molarity of HCl [tex]\rm[/tex][tex]\times[/tex] Volume of HCl = Molarity of NaOH

Given,

The volume of HCl solution = 25 ml

Molarity of NaOH = 0.125 M

Volume of NaOH solution = 43.6 ml

Substitute the values in the equation:

Molarity of HCl [tex]\times[/tex] 25 = 0.125 [tex]\times[/tex] 43.6

Molarity of HCl [tex]\times[/tex] 25 = 5.45

Molarity of HCl solution = [tex]\rm \dfrac{5.45}{25}[/tex]

Molarity of HCl solution = 0.218 M

The molarity of the HCl solution used in the neutralization reaction has been 0.218 M.

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Answer:

The unbalanced chemical equation is

K

2

Cr

2

O

7

+HCl→KCl+CrCl

3

+H

2

O+Cl

2

Balance all atoms except H and O.

K

2

Cr

2

O

7

+10HCl→2KCl+2CrCl

3

+H

2

O+Cl

2

Assign oxidation numbers.

K

2

+6

Cr

2

O

7

+10H

−1

Cl

→2KCl+2

+3

Cr

Cl

3

+H

2

O+

0

Cl

2

The oxidation number of Cr decreases from +6 to +3. Total decrease in the oxidation number of two Cr atoms is 6. The oxidation number of Cl increases from -1 to 0. Total increase in the oxidation number of 2 Cl atoms is 2.

Balance increase in oxidation number with decrease in oxidation number by using appropriate coefficients.

K

2

Cr

2

O

7

+14HCl→2KCl+2CrCl

3

+H

2

O+3Cl

2

Balance O atoms by adding six water molecules on products side.

K

2

Cr

2

O

7

+14HCl→2KCl+2CrCl

3

+7H

2

O+3Cl

2

H atoms are balanced.

K

2

Cr

2

O

7

+14HCl→2KCl+2CrCl

3

+7H

2

O+3Cl

2

This is balanced chemical equation.

The sum of the coefficients of the products is 2+2+7+3=14

Answer:

I) 1 mol of SO3(g)

2) 1 mol of CO2(g)

3) 3 mol of O2(g)

4) 1 mol of KBr(aq)

5) Seawater at 23°C

6) 1 mol of CCl4(g)

Explanation:

In molecules having greater numbers of atoms, there is an increase the number of ways by which the molecule vibrates thereby leading to a higher number of possible microstates and overall increase in entropy of the system. Hence, 1 mol of SO3(g) has a higher entropy than 1 mol of SO2.

Gases have a higher entropy than liquids and liquids have a higher entropy than gases.

Also, the greater the molecular weight of a molecule, the higher the entropy. Higher number of moles of a gas as well as the increase in temperature of a substance are also factors that lead to higher entropy.

Answer:

A sample of calcium fluoride was decomposed into the constituent elements. Write a balanced chemical equation for the decomposition reaction. If the sample produced 294 mg of calcium, how many g of fluorine was formed

Explanation:

The balanced chemical equation for the decomposition of calcium fluoride is shown below:

[tex]CaF_2(s)->Ca(s)+F_2(g)[/tex]

The sample produced 294 g of calcium then, how many grams of fluorine is formed?

From the balanced chemical equation,

1 mol of CaF2 forms 1mol of calcium and 1 mol of fluorine.

That is:

40g of calcium and 38.0 g of fluorine are formed.

then,

If 294 g of calcium is formed then how many grams of fluorine is formed?

[tex]294g Ca * 38g F2 / 40g Ca\\=279.3 g F_2[/tex]

Hence, 279.3 g of fluorine will be formed.

Answer: There are [tex]1.23 \times 10^{22}[/tex] atoms present in 37.1 mg of tantalum.

Explanation:

Given: Mass of single tantalum atom = [tex]3.01 \times 10^{-22} g[/tex]

Mass of tantalum atoms = 37.1 mg (1 mg = 0.001 g) = 0.0371 g

Therefore, number of tantalum atoms present in 0.0371 grams is calculated as follows.

[tex]No. of atoms = \frac{0.0371 g}{3.01 \times 10^{-22}}\\= 1.23 \times 10^{20}[/tex]

Thus, we can conclude that there are [tex]1.23 \times 10^{22}[/tex] atoms present in 37.1 mg of tantalum.

There are [tex]1.23\times 10^{20}[/tex] atoms of tantalum in 37.1 mg of tantalum.

Explanation:

Given:

Mass of single atom of tantalum =[tex]3.01\times 10^{-22} g[/tex]

To find:

The number of atoms of tantalum in 37.1 milligrams.

Solution:

Mass of tantalum = 37.1 mg

[tex]1 mg = 0.001 g\\37.1 mg=37.1\times 0.001 g=0.0371 g[/tex]

The number of atoms in 0.0371 grams of tantalum = N

Mass of a single atom of tantalum = [tex]3.01\times 10^{-22} g[/tex]

Then a mass of N atoms of tantalum will be:

[tex]0.0371 g=N\times 3.01\times 10^{-22} g\\N=\frac{0.0371 g}{ 3.01\times 10^{-22} g}\\=1.23\times 10^{20}[/tex]

There are [tex]1.23\times 10^{20}[/tex] atoms of tantalum in 37.1 mg of tantalum.

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The question is incomplete, the complete question is;

It takes 338. kJ/mol to break an carbon-chlorine single bond. Cal broken by absorbing a single photon Iculate the maximum wavelength of light for which an carbon-chiorine single bond could be Round your answer to 3 significant digits

Answer:

3.55 × 10^-7 m or 355 nm

Explanation:

Now, the energy of the photon = 338 × 10^3/6.02 × 10^23 = 5.61 × 10^-19 J

Recall that;

E= hc/λ

h= planks constant

c= speed of light

λ = wavelength

λ =hc/E

λ = 6.63 ×10^-34 × 3 × 10^8/5.61 × 10^-19

λ =3.55 × 10^-7 m or 355 nm

Answer:

C₆H₁₈O₉

Explanation:

First we calculate the molar mass of the compound represented by the empirical formula:

Then we divide the given formula mass by the calculated molar mass:

Thus we multiply by 3 the subscripts in the empirical formula:

Answer:

answer is first one 1 will be less then that of hg coloumn

Answer:

Carboxyl, primary amine, amide, ester, and phenyl.

Explanation:

The functional groups present in the compound of aspartame are carboxyl, primary amine, amide, ester, and phenyl. Aspartame is an artificial non-saccharide sweetener which is 200 times sweeter than sucrose. This aspartame is commonly used as a sugar substitute in many foods and beverages. It has the trade names such as NutraSweet, Equal, and Canderel.

Answer:

Each of the following reactions was in equilibrium when the pressure of their containers was doubled. Chose which way the reaction shifted after the pressure change:

2NH3 (g)->N2(g) +3H2(g)

2Na3 PO4 (aq) + 3CaCl2 (aq) -> Ca3 (PO4 )2 (s) + 6NaCl(aq)  

2CO(g)+O2 (g)->2CO2 (g)  

2HI(g) -> H2(g) + I2(g)

Explanation:

Effect of pressure on equilibrium:

When pressure is increased on an equilibrium system,then equilibrium will shift in such a direction towards less number of moles of substrates.

For the first system,

2NH3 (g)->N2(g) +3H2(g)

increase in pressure,shifts the equilibrium towards the left side that is the formation of ammonia is favored.

For the second reaction:

2Na3 PO4 (aq) + 3CaCl2 (aq) -> Ca3 (PO4 )2 (s) + 6NaCl(aq)

The quilibrium will shift towards right.

Becuase right side less number of moles of substrates are there.

2CO(g)+O2 (g)->2CO2 (g)

For this system,the equilibrium will shift towards right side that is formation of CO2 gas is favored.

For the last system,

2HI(g) -> H2(g) + I2(g)

there is no effect of pressure.

Becuase the number of moles of substrates are same on both sides.

Answer:

Certain ketones such as fructose can be oxidized by Benedict's reagent under basic conditions to form what type of compound

Explanation:

Benedict's solution is a mixture of copper sulfate, anhydrous sodium carbonate, and sodium citrate.

In presence of mild reducing agents, Cu(II) ion in Benedict's solution becomes the Cu(I) ion.

Fructose has an alpha-hydroxy ketone group.

It undergoes tautomerism and forms alpha-hydroxy aldehyde which gives a positive test with Benedict's reagent.

During this test, aldehydes will be converted into carboxylic acids.

The reaction of fructose with Benedict's reagent is shown below:

Answer:

The rate of change of T with respect to time is 0.40 K/min

Explanation:

The gas law equation is:

[tex] PV = nRT [/tex]

We can find the rate of change of T with respect to time by solving the above equation for T and derivating with respect to time:

[tex] \frac{dT}{dt} = \frac{d}{dt}(\frac{PV}{nR}) [/tex]

[tex] \frac{dT}{dt} = \frac{1}{nR}(V\frac{dP}{dt} + P\frac{dV}{dt}) [/tex]

Where:

n: is the number of moles = 10 mol

R: is the gas constant = 0.0821

V: is the volume = 13 L

P: is the pressure = 8.0 atm

dP/dt: is the variation of the pressure with respect to time = 0.13 atm/min

dV/dt: is the variation of the volume with respect to time = -0.17 L/min

Hence, the rate of change of T is:

[tex] \frac{dT}{dt} = \frac{1}{10*0.0821}(13*0.13 - 8.0*0.17) = 0.40 K/min [/tex]    

Therefore, the rate of change of T with respect to time is 0.40 K/min

I hope it helps you!    

Ionic bonds are the strongest type of chemical bond and, therefore, most compounds remain solid with very high melting points

The statement best describes the strength of ionic and covalent bonds is that ionic bond is the strongest bond and has very high melting point.

A chemical bond is a lasting attraction between atoms or ions that enables the formation of molecules, crystals, and other structures. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds, or through the sharing of electrons as in covalent bonds.

Types of Chemical Bonds includes-

Ionic Bonds.

Covalent Bonds.

Hydrogen Bonds.

Polar Bonds.

Generally, ionic bonds are much stronger than covalent bonds. In ionic bonds, there is complete transfer of electrons between elements to form a stable compound. While in covalent bond, there is only sharing of electrons between two elements to form a stable compound.

Therefore, The statement best describes the strength of ionic and covalent bonds is that ionic bond is the strongest bond and has very high melting point.

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#SPJ2

Answer:

10.1 h

Explanation:

Let's consider the reduction half-reaction of iron from an aqueous solution of iron (III) chloride.

Fe³⁺(aq) + 3 e⁻ ⇒ Fe(s)

We can calculate the time required to produce 5.00 moles of Fe using the following relationships.

[tex]5.00molFe \times \frac{3 mole^{-} }{1molFe} \times\frac{96486C}{1mole^{-} } \times \frac{1s}{40.0C} \times \frac{1h}{3600s} = 10.1 h[/tex]

Answer:

290 g Al₂O₃

General Formulas and Concepts:

Atomic Structure

Stoichiometry

Explanation:

Step 1: Define

[Given] 2.8 mol Al₂O₃

[Solve] g Al₂O₃

Step 2: Identify Conversions

[PT] Molar Mass of Al: 26.98 g/mol

[PT] Molar Mass of O: 16.00 g/mol

Molar Mass of Al₂O₃: 2(26.98) + 3(16.00) = 101.96 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

285.488 g Al₂O₃ ≈ 290 g Al₂O₃

Topic: AP Chemistry

Unit: Atomic Structure

Explanation: The hypothesis is a prediction, but it involves more than a guess. Most of the time, the hypothesis begins with a question which is then explored through background research. It is only at this point that researchers begin to develop a testable hypothesis.

(Unless you are creating an exploratory study, your hypothesis should always explain what you expect to happen)

Answer:

Earth has a mass of 5.9736×1024 kg

hope it is helpful to you

Answer:

SF2(aq) → S²⁺(aq) + 2F-(aq)

Explanation:

The sulfur difluoride, SF2, dissolves in water because the differences in electronegativities are considerable (3.98 for Fluorine and 2.58 for S) doing the F-S bond polar. As water is a polar solvent will dissolve the SF2 as follows:

As Fluorine has a > electronegativity than S, the Fluorine will be negative and S will be positive. Also, all halogen ions has a charge of -1.

Answer:

1. not enough dye was added to the drink.

The wrong dye was added to the drink

the water in the drink is evaporating

2. Changing the compound changes the absorbance behavior.

3. Measure the absorbance for the same solution in different cuvette sizes and find the y-intercept.

Explanation:

When the beverage company adds dye to the drink, there should be standard quantity added to the drink so that the color of the drink remains constant. When too much dye is added to the drink, the color will get dark brown or black. When the color of drink get lighter than green this means dye is not added in required quantity.

Answer:

No

Explanation:A single property is insufficient for identifying a substance

Complete question is;

Identify the type of reaction in the chemical reaction below:

2P205 ➡️ 4P + 502

single replacement

synthesis

decomposition

combustion

double replacement

Answer:

Decomposition

Explanation:

We. An see in the question that the compound 2P205 is broken down into simpler substances which are phosphorus (P) and oxygen (O).

Now, this is a decomposition reaction because a decomposition reaction is one in which a compound is broken down into simpler substances

hope it helps to everyone

Answer:

Benzoic acid= 37.16%

Naphthalene = 24.43%

3-Nitroaniline= 29.38%

Explanation:

Data given:

percentage recovery of benzonic acid = 9.75/26.24 * 100 = 37.16%

Percentage recovery of napthalene = 6.41/26.24 * 100 = 24.43%

Percentage recovery of 3-nitroaniline = 7.71/26.24 * 100 = 29.38%

A is the answer

In an ozone molecule, the three atoms must be connected, so there must at least be a single bond between them. Place

dots in pairs around the oxygen atoms until each oxygen atom has eight valence electrons, starting with the atoms on the

outside and doing the central atom last if there are enough. Do not exceed the total number of valence electrons

identified in part A. Remember that the dashes between the oxygen atoms, which represent single bonds, each indicate

the presence of two valence electrons

Answer:

Explanation: i did it

Answer:

green gemstone

Explanation:

hope this helps someone