Based on this information what is the most likely reason for refrigerating most foods reduce the rate at which they spoil

Answer:  Pb(NO3)2(aq) + 2KI(aq)  —> PbI2(s) + 2KNO3(aq)

1.57x10^22 atoms of Pb

87% yield

Explanation:

10.0 g Pb(II) nitrate = 10/333 moles = 0.03 moles

12.0 g KI = 12/166 moles = 0.072 moles (0.06 moles required)

11.4 g PbI2 = 11.4/421 moles = 0.026 moles

expected yield 0.03 moles, yield = 87%

atoms in 11.4 g = 0.026 moles = 0.026*6.02214076*10^23 atoms = 1.57*10^22

Answer:

840960 minutes in 1.6 years ...

Answer:

Explanation:

aluminum

Answer: The aluminum ion

Explanation:

Answer:

Explanation:

Alcohols can be oxidised by a variety of oxidising agents. Sodium or potassium dichromate acidified with dilute sulphuric acid can bring about oxidation in straight chained alcohols.

Answer:

2-methylbutan-1-ol is oxidised by potassium dichromate: 2-methylbutan-1-ol + [O] ==> 2-methylbutan-1-al + water CH3CH2CH(CH3) CH2OH + [O] ==> CH3CH2CH(CH3) CHO + H2O

Explanation:

A hypothetical AX2 type of ceramic material has a density of 12.59g/cm3 and a unit cell of cubic symmetry with  cell edge length of 0.54 nm, then  the crystal structures possible for this material is C.) Fluorite.

Fluorite is the mineral form of calcium fluoride, CaF₂ and belongs to the halide minerals. The Mohs scale of mineral hardness that is based on the scratch hardness comparison defines the value 4 as fluorite.

Fluorites contain fluorine as a part of their chemical makeup (CaF2). Fluorine is very toxic as a gas but fluorites are inert. Wearing or holding fluorite gems or jewelry does not pose any health risks.

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Answer:

Explanation:

Atomicity is defined as the total number of atoms present in a molecule.

Answer: The Marshmellow

Explanation

The marshmallow turns from a solid to a gooey texture.

As per the given data, 1.6 grams of oxygen reacted in this experiment.

To calculate the amount of oxygen that reacted in the experiment, we need to determine the difference in the mass of X oxide (X,O) formed and the mass of X initially used.

Given:

Mass of X = 4.6 g

Mass of X oxide (X,O) = 6.2 g

To find the amount of oxygen that reacted:

Mass of oxygen = Mass of X oxide - Mass of X

= 6.2 g - 4.6 g

= 1.6 g

Therefore, 1.6 grams of oxygen reacted in this experiment.

Calculate the mass of 1 mole of X:

Given that the mass of X is 4.6 g, we can calculate the molar mass of X by dividing the mass by the number of moles:

Molar mass of X = Mass of X / Number of moles of X

Molar mass of X = 4.6 g / 0.1 mol

Molar mass of X = 46 g/mol

Therefore, the mass of 1 mole of X is 46 grams.

Thus, the answer is 46 grams.

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Answer:

sodium chloride can be used as salt

extraction sodium metal by electrolysis

a common chemical in laboratory experiments

Answer:

sodium chloride can be used as preservatives,

in preserving foods.

The car's average speed is 116 kilometers per hour.

The entire distance traveled divided by the total time elapsed is the definition of average speed. It is typically stated in terms of the amount of time or distance per unit, such as meters per second (m/s) or kilometers per hour (km/hr).

Average speed = total distance ÷ total time

In this case, the total distance is 464 km and the total time is 4 hours.

Average speed = 464 km ÷ 4 hours

Average speed = 116 km/hr

Therefore, the car's average speed is 116 kilometers per hour.

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Answer:

wavelength, λ =  486.6 nm

frequency, f = 6.16 * 10¹⁴ Hz

Explanation:

a. Wavelength

Using the wavelength equation; 1/λ = (1/hc) * 2.18 * 10⁻¹⁸ J * (1/nf² - 1/ni²)

Where nf is the final energy level; ni is the initial energy level; h is Planck's constant = 6.63 * 10⁻³⁴ J.s; c is velocity of light = 3 * 10⁸ m/s

1/λ = 1/(6.63 * 10⁻³⁴ J.s * 3 * 10⁸ m/s) * 2.18 * 10⁻¹⁸ J * (1/2² - 1/4²)

1/λ = 2.055 * 10⁶ m

λ = 4.866 * 10⁻⁷ m

wavelength, λ =  486.6 nm

b.  Frequency

Using f = c/λ

f = (3 * 10⁸ m/s) / 4.866 * 10⁻⁷ m

frequency, f = 6.16 * 10¹⁴ Hz

Answer:

0.0505

Explanation:

Step 1: Calculate the masses of solute and solvent

We have a 15.7% by mass nitric acid solution, that is, there are 15.7 g of nitric acid (solute) per 100 g of solution. The mass of water (solvent) is:

m(solution) = m(solute) + m(solvent)

m(solvent) = m(solution) - m(solute)

m(solvent) = 100 g - 15.7 g = 84.3 g

Step 2: Calculate the moles of nitric acid

The molar mass of nitric acid is 63.01 g/mol.

15.7 g × (1 mol/63.01 g) = 0.249 mol

Step 3: Calculate the moles of water

The molar mass of water is 18.02 g/mol.

84.3 g × (1 mol/18.02 g) = 4.68 mol

Step 4: Calculate the mole fraction of nitric acid

\(X(HNO_3) = \frac{nHNO_3}{nHNO_3+nH_2O} = \frac{0.249mol}{0.249mol+4.68mol} = 0.0505\)

Answer:

0.99 μmol/L

Explanation:

From the question given above, the following data were obtained:

Volume of stock solution (V₁) = 20 mL

Concentration of stock solution (C₁) = 18.8 μmol/L

Volume of diluted solution (V₂) = 380 mL

Concentration of diluted solution (C₂) =?

The concentration of the diluted solution can be obtained as follow:

C₁V₁ = C₂V₂

18.8 × 20 = C₂ × 380

376 = C₂ × 380

Divide both side by 380

C₂ = 376 / 380

C₂ = 0.99 μmol/L

Therefore, the concentration of the diluted solution the chemist is working on is 0.99 μmol/L

False, if a pill is tested with formaldehyde and sulfuric acid and turns the solution orange, it does not necessarily mean that ecstasy was present.

While ecstasy does produce this reaction, other substances can as well. Formaldehyde and sulfuric acid are reagents used in the “Marquis test” to identify the presence of certain alkaloids. When these two chemicals are mixed together, a reaction will occur with certain compounds to produce an orange solution.

This reaction can occur with other substances like codeine, heroin, and even caffeine. Therefore, the orange solution is not a definitive indicator of the presence of ecstasy.

To identify the exact substance, a sample of the pill must be tested using a more advanced method such as a gas chromatography–mass spectrometry or high performance liquid chromatography (HPLC). These methods can accurately identify the exact components of the pill. while the Marquis test can be used as a preliminary test to identify the presence of certain compounds, it cannot definitively determine if ecstasy was present.

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Answer:

the uber driver

Explanation:

Answer:

cooking food stuff rusting

Explanation:

Answer:

Signs of chemical reactions are, if gas or bubbles are present, if a color changes occurs, or if a precipitate is formed, that could indicate that a chemical reaction has occurred

Explanation:

Answer:

A

Explanation:

Answer:

mass of sodium phosphate required = 25.37 g

Explanation:

Equations of reactions:

3CaCl₂ + 2Na₃PO₄ ---> Ca₃(PO₄)₂ + 6NaCl

3Mg(NO₃)₂ + 2Na₃PO₄ ---> Mg₃(PO₄)₂ + 6NaNO₃

Number of moles of the ions = molarity x volume

Ca²⁺ : 0.052 M x 1.6 L = 0.0832 moles

Mg²⁺ : 0.093 x 1.6 L = 0.1488 moles

From the equations of reaction, number of moles of sodium phosphate required to react with each ion is given as;

For calcium: 2/3 x 0.0832 = 0.0555 moles

For magnesium: 2/3 x 0.1488 = 0.0992 moles

Total number of moles of sodium phosphate required = 0.0555 + 0.0992 = 0.1547 moles

Mass of sodium phosphate = number of moles x molar mass

molar mass of sodium phosphate = 164 g/mol

Mass of sodium phosphate = 0.1547 moles x 164 g/mol = 25.37 g

Therefore, mass of sodium phosphate required = 25.37 g

Doing a greater amount of work than the of work done on the machine is impossible for a machine to do. The energy given the system might loss some fraction and cannot be converted completely to output work.

Work done is a physical quantity that describes the result of a force or how effectively the force made a displacement. The force applied on a body if results in a displacement of the body, the force is said to be done work on the body.

Work done is a vector quantity, having both magnitude and direction. According to thermodynamic concept, then it is impossible to convert all the input energy into work done.

It is impossible to achieve a 100% of efficiency or more by a machine. Hence, doing greater amount of work than the input is impossible for a machine.

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Answer:

A or do a greater amount of work than the amount of work done on the machine

Explanation:

Bc i did the test in edge

Answer:

The Lewis structure for the sulfate ion consists of a central sulfur atom with four single bonds to oxygen atoms. This yields the expected total of 32 electrons. Since the sulfur atom started with six valence electrons, two of the S-O bonds are coordinate covalent.

Explanation:

Then that means it has both.

Answer: 29.4 Grams!

Explanation:

The answer is 29.4 grams of oxygen atoms. This is because 14.7 grams of carbon dioxide is made up of 1 molecule of carbon and 2 molecules of oxygen, meaning that for every 14.7 grams of carbon dioxide, there are 29.4 grams of oxygen atoms.

The statement which correctly describes the energy of the particles of the substance for point D to E is that Potential energy increases and average kinetic energy remains the same which is therefore denoted as option 3.

This is referred to as the energy possessed by a body by virtue of its motion while potential energy is the energy possessed by a body by virtue if its position.

The graph shown depicts that temperature is constant from point D to E which means that the particles are at a position which depicts potential energy.

Temperature is referred to as the average kinetic energy of molecules which ius therefore the reason why a constant temperature also means that  the average kinetic energy remains the same which is therefore the reason why it was chosen as the correct choice.

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Cuso4 + NaoH -》cu(oH)2 +Na2So4

Cuso4 + 2NaoH -》cu(oH)2 +Na2So4

Explanation:

this is balanced equation

Therefore, approximately 235.6 grams of Sulfuric Acid can be produced from 422 grams of iron ore containing 75.0% Iron(II) sulfide.

During such a titration, sulfuric acid is added to maintain the medium's acidity and meet the stoichiometric needs of the redox reaction. Additionally, extra amounts are injected to supply the protons (H+) needed for the redox reaction.

We can begin by figuring out how much Iron(II) sulfide there is in the 422 grammes of iron ore:

mass of FeS = 422 g x 0.75 = 316.5 g

We can see from the equation that everything balances out that 1 mol of FeS combines with 1.5 mol of sulfur dioxide to create 1 mol of Sulfuric Acid. Therefore, we must first determine the amount of Iron(II) sulfide in moles:

moles of Iron(II) sulfide = mass of Iron(II) sulfide / molar mass of Iron(II) sulfide

moles of Iron(II) sulfide = 316.5 g / 87.91 g/mol

moles of Iron(II) sulfide = 3.597 mol

Next, we can determine the quantity of moles of Sulfuric Acid generated using the stoichiometric ratios from the balanced equations:

1 mol sulfur dioxide : 1.5 mol sulfur dioxide : 1 mol Sulfuric Acid

3.597 mol : 5.3955 mol : x mol Sulfuric Acid

x mol Sulfuric Acid = (3.597 mol Iron(II) sulfide) x (1 mol Sulfuric Acid / 1 mol FeS) x (1.5 mol sulfur dioxide / 1 mol FeS) x (1 mol Sulfuric Acid / 1.5 mol SO2)

x mol H2SO4 = 2.398 mol

Finally, we can determine the mass of created Sulfuric Acid:

mass of Sulfuric Acid = moles of Sulfuric Acid x molar mass of Sulfuric Acid

mass of Sulfuric Acid = 2.398 mol x 98.079 g/mol

mass of Sulfuric Acid = 235.6 g.

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Answer: 1.85 (D)

Explanation:

D is the solution to this question

Answer:

the community needs to work alongside with government and religious organisations. the communities work on both profile and non profile work incase of human rights violations. they also force the government to take necessary action

Explanation:

Description. Regardless of the type of hydrocarbon, combustion with oxygen produces 3 products: carbon dioxide, water and heat, as shown in the general reaction below.

Answer:

*  Properly dispose of hazardous household items.

*  Reduce or eliminate use of fertilizers and chemical herbicides and           pesticides.

*  Make an appointment to service your septic system

Landscape with native plants.

*  Eliminate bare spots in your yard.

*  Make a rain garden.

WAS THIS HELPFUL......

1. The number of mole of C₃H₈ needed to make 15.5 moles of CO₂ is 5.2 moles

2. The number of moles of O₂ needed is 25.8 moles

The number of mole of C₃H₈ needed can be obtained as illustrasted below:

C₃H₈ + 5O₂ -> 3CO₂ + 4H₂O

From the balanced equation above,

3 moles of CO₂ was obtained from 1 mole of C₃H₈

Therefore,

15.5 moles of CO₂ will be obtain from = (15.5 × 1) / 3 = 5.2 moles of C₃H₈

Thus, number of mole of C₃H₈ needed is 5.2 moles

We can obtain the number of mole of O₂ needed as follow:

C₃H₈ + 5O₂ -> 3CO₂ + 4H₂O

From the balanced equation above,

3 moles of CO₂ was obtained from 5 moles of O₂

Therefore,

15.5 moles of CO₂ will be obtain from = (15.5 × 5) / 3 = 25.8 moles of O₂

Thus, number of mole of O₂ needed is 25.8 moles

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Complete question:

How many moles of C₃H₈ are needed to make

15.5 moles of CO₂? How much O₂ will be needed?

C₃H₈ + 5O₂ -> 3CO₂ + 4H₂O