uses of radio isotopes​

Answer: The concentration of lead nitrate Pb(NO3)2 in a 0.726 M solution is 0.755 molal.

Explanation:

Given:

The molar mass of Pb(NO3)2 is 331.2 g/mol

Assuming 1 litre of solution.  This would equal 1202 g of solution

In the one litre of solution, you have 0.726 mol Pb(NO3)2

0.726 mol (331.2 g/mol) = 240.5 g Pb(NO3)2

Mass of water in 1 L of solution = 1202 g - 240.5 g = 961.5 g = 0.9615 kg

Molality = mols of solute / kg of solvent

= 0.726 mol / 0.9615 kg

= 0.755 m Pb(NO3)2

Lead will have the highest temperature .

What is Specific Heat ?

Specific Heat is defined as the amount of heat required to raise the temperature of a 1 gm of substance by 1 degree Celsius.

If heat is added to 25.0g of copper, calcium, aluminum, iron, lead

The missing given specific heat is

Copper, 0.377

Calcium, 0.656

Aluminum, 0.895

Iron, 0.448

Lead, 0.129

Higher specific heat means more temperature required to bring the same amount of change in temperature

Here the temperature change is fixed , The metal with the lowest Specific heat will have the highest temperature.

From the data it can be seen that

Specific Heat of Lead, 0.129

Therefore Lead will have the highest temperature.

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Based on the oxidation-reduction potential of the system, ratio of the concentration of the oxidized form to the concentration of the reduced form is 1 : 10.

The oxidation-reduction potential of a system is a measure of the tendency for a given chemical species to be reduced.

The reduction equation is as follows:

[tex]Fe^{3+} \rightarrow Fe^{2+} = 0.77\:V[/tex]

Using the equation:

[tex]E = E^{o} - \frac{0.0592}{n}log\frac{[Fe^{2+}]}{[Fe^{3+}]}[/tex]

n = 1; E⁰ = 0.77; E = 0.711

Substituting the values and using 1/x as the ratio:

[tex]0.711 = 0.77 - \frac{0.0592}{1} * log\frac{1}{x}[/tex]

x = 1/10

Therefore, the ratio of the concentration of the oxidized form to the concentration of the reduced form is 1 : 10.

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Answer:

Explanation:Hyaluronic acid is a natural substance found in the fluids in the eyes and joints. It acts as a cushion and lubricant in the joints and other tissues.

Different forms of hyaluronic acid are used for cosmetic purposes. Hyaluronic acid might also affect the way the body responds to injury and help to decrease swelling.

Hyaluronic acid injections are US FDA-approved for several conditions, including cataracts, osteoarthritis, and as an injectable gel filler (Juvedérm) for facial wrinkles. People also commonly take hyaluronic acid by mouth and apply it to the skin for UTIs, acid reflux, dry eyes, wound healing, aging skin, and many other conditions, but there is no good scientific evidence to support most of these other uses.

How does it work ?

Uses & Effectiveness ?

Likely Effective for

Cataracts. Injecting hyaluronic acid into the eye is effective when used during cataract surgery by an eye surgeon.

Swelling (inflammation) and sores inside the mouth (oral mucositis). Applying an FDA-approved hyaluronic acid gel is effective for treating mouth sores. It's not clear if other products help.

Answer:

Explanation:

Hyaluronic acid is a natural substance found in the fluids in the eyes and joints. It acts as a cushion and lubricant in the joints and other tissues. Different forms of hyaluronic acid are used for cosmetic purposes. Hyaluronic acid might also affect the way the body responds to injury and help to decrease swelling.

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Answer:

1) mass and type of material

2) type of material

3) temperature

Explanation:

Answer:

For Ed

Explanation:

The first one is: The physical proprieties.

The second one is: The pH of the solution.

I've been seeing the same answers from above around though, so I may be wrong. But either way, I tried.

Synthetic materials are made from natural resources and can be used for many purposes.

Synthetic materials are made by chemically changing the starting substances to create a material with different characteristics. Some examples of synthetic materials are plastics, medicines, and new fuels.

A synthetic substance may be chemically identical to a naturally-occurring substance or may be different.

Item is made from a synthetic material :

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When 1 mole of Zn and 2 mole of O₂ reacts togethor, It will produce 1 mole of ZnO as O₂ is excess reagent and Zn will act as Limiting reagent and thus it limits the amount of product formed.

Limiting reagents are the substances that are completely consumed first in a chemical reaction.

Given ;

Given equation ;

2Zn + O₂ --> 2ZnO

As according to given chemical equation,

2 moles Zn of reacts with 1 mole of O₂ to produce 2 moles of ZnO.

Therefore,

1 mole of Zn will require 0.5 mole of O₂.

But,

the given amount of O₂ is 2 mole which is excess

Hence,

Zn here will act as the Limiting reagent, According to which the amount of product formed will be decided.

Therefore,

If 2 mole Zn produces : 2 moles of ZnO (According to given balanced equation)

Thus,

1 mole of Zn will produce = 2/2 x 1

                                          = 1 mole of ZnO

Hence, When 1 mole of Zn and 2 mole of O₂ reacts togethor, It will produce 1 mole of ZnO as O₂ is excess reagent and Zn will act as Limiting reagent and thus it limits the amount of product formed.

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Answer:

162 g Fe₂O₃

Explanation:

To find the mass of Fe₂O₃, you need to (1) convert grams C to moles C (via molar mass from periodic table), then (2) convert moles C to moles Fe₂O₃ (via mole-to-mole ratio from reaction coefficients), and then (3) convert moles Fe₂O₃ to grams (via molar mass). It is important to arrange the ratios/conversions in a way that allows for the cancellation of units. The final answer should have 3 sig figs to reflect the given value.

Molar Mass (C): 12.011 g/mol

2 Fe₂O₃(s) + 3 C(s) ---> 4 Fe(s) + 3 CO₂(g)

Molar Mass (Fe₂O₃): 2(55.845 g/mol) + 3(15.998 g/mol)

Molar Mass (Fe₂O₃): 159.684 g/mol

18.3 g C           1 mole            2 moles Fe₂O₃          159.684 g
--------------  x  ----------------  x  -------------------------  x  -----------------  = 162 g Fe₂O₃
                        12.011 g              3 moles C                 1 mole

Answer:

which is an example of analog device

Due to the reaction's slow process of producing ppt or a change in color.

Chemical reaction is defined as a procedure where one or more compounds, known as reactants, are changed into one or more new substances, known as products. Chemical reactions result in the formation of new chemical bonds between the atoms of the reactant molecules and the product particles' atoms. While there are the same number of atoms both before and after the chemical transition, there will be a change in the number of molecules.

When carbon dioxide and water combine, carbonic acid is created. The indicator changes color as a result of the water becoming slightly acidic due to carbon dioxide gas from exhaled breath. Dissolution causes a change in pressure. This suggests a physical alteration.

Thus, due to the reaction's slow process of producing ppt or a change in color.

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Answer: 50.806 cm is the correct answer.

Explanation: First divide 6104.5 cm^2 by 22.3 cm.

[tex]\frac{6104.5cm^2}{22.3cm} = 273.74 cm[/tex]

*Note: When dividing units, subtract the exponents, and when multiplying units simply add the exponents.

Then continue by subtracting 324.55 cm - 273.74 cm.

This should give you an answer of 50.806 cm.

M = n/V

V = n/M

V = (14.5 : 56.1056)/2.8

V = 0.0923 L = 92.3 mL

V=n/M

V=(6.34:125.55 g/mol)/0.72

V=0.07 L = 70 ml

Your question's data is not correct, it should be 100 grams of limestone instead of 10 grams, You will find the correct solution below according to that.

The percentage purity of calcium carbonate is 82.5%

The balanced chemical equation is

CaCO₃ + 2HCl  →  CaCl₂ + H₂O + CO₂

Because CO₂ is a gas, you can easily convert it to mole directly

No. of mol of CO₂ = volume dm³ /22.4 dm³

No. of mol of CO₂ = 8.5 dm³ / 22.4 dm³

No. of mol of CO₂ = 0.825 mol

According to equation 1 mole of CO2 is made from 1 mole of CaCO3

So, 0.825 mole of CO2 will be made from 0.825 mole of CaCO3

Mass of CaCO3 = moles of CaCO3 × Molar mass of CaCO3

Mass of CaCO3 = 0.825 × 100 grams

Mass of CaCO3 = 82.5 grams

Percentage purity of CaCO3 = (mass of CaCO3/Total mass of CaCO3) × 100

Percentage purity of CaCO3 = (82.5/100) × 100 %

Percentage purity of CaCO3 = 82.5 %

Thus we can say that as percentage purity is the percentage of mass of pure compound on per unit of total compound, the percentage purity of the calcium carbonate will be 82.5 %

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Answer:

Make life easy for your customers and they are more likely to come back and buy again.

Explanation:

For example, you have to hire the right talent. You don't want somebody on the job that doesn't know how to do anything.

The conversion of heat to kinetic energy inside the water molecules causes the motion of the molecules to increase. The distance between molecules widens when the molecules move more quickly and clash more frequently. (As more heat is absorbed, the distance between molecules for solids, liquids, and gases widens)

The error caused will lower the number of moles when he did not do the second heating.This question is related to the empirical formula.

A formula giving the proportions of the elements present in a compound but not the actual numbers or arrangement of atoms.

The empirical formula is the simplest ratio of atoms in a given compound.

we know that heating is used to eliminate most of the water molecules which are attached to the compound in the question, it's given that the second heating was not performed by the students.

This means that there are still some water molecules attached to the compound. This will imply that higher mass will be calculated for the compound because the water molecules are also considered.

So now, if we look at the calculation for the number of moles of water in this, we can say that this will be lower than the actual amount.

This is because there are some unaccounted moles of water which are still attached to the compound and these will be accounted in the compound mass rather than the waters. Therefore, the number of moles will be lower.

Hence, The error caused will lower the number of moles when he did not do the second heating.

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Answer:

55.5g of calcium chloride is produced in the reaction.

Explanation:

To calculate the amount of calcium chloride.

The reaction of calcium carbonate with hydrochloride acid gives calcium chloride

CaCO₃ +  2HCl  →  CaCl₂  + CO₂  +  H₂O

Mass of calcium carbonate (CaCO₃)= 50.0g

Molecular mass of CaCO₃ = Ca + C + O₃

                                             = 40+ 12 + 3(16) = 100g

No of moles of calcium carbonate CaCO₃ = given mass / molecular mass

                                                                          = 50g/ 100

                                                                            = 0.5 moles

Molecular mass of calcium chloride = 40+ 2(35.5)=(40+71.0)= 111g/mol

1 mole of calcium carbonate gives = 1 mole of calcium chloride

0.5 moles of calcium carbonate gives= 0.5 × 111g/mole

                                                                = 55.5g

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C. Double replacement

cations and anions switch places

2Li + 2H2O____ 2LiaOH + 2H2

Answer:

2 Li + 2 H2O --> 2 LiaOH + 1 H2

Answer:

5.96 * 10^23 molecules

Explanation:

Don't start counting up the number of CsHsNs and Os there are Counting up the atom ions will get a wrong answer.  The question is asking for the number of molecules. That means you do not break down each molecule to  find the number of molecules. You modify 1 mol to find out how many molecules are in 0.99 mols. Do that using a proportion.

1 mol contains 6.01 * 10^23 molecules

0.99 mol contains x

1/0.99 = 6.02 * 10^23 / x molecules

x = 0.99 * 6.02 * 10^23

x = 5.96 * 10^23

Answer:

Density = 0.0035 g/cm³

Explanation:

The density equation looks like this:

Density (g/cm³) = mass (g) / volume (cm³)

You have been given both the mass and volume. However, the given volume is not in the correct units. To convert cm to cm³, you should simply raise the given volume to the power of 3.

24 cm  =  (24 cm)³  =  24³cm³  =  13,834 cm³

Now, you can plug you mass and volume into the equation and solve for density. The final answer should have 2 sig figs to reflect the given values.

Density = mass / volume

Density = 48 g / 13,824 cm³

Density = 0.00347 g/cm³

Density = 0.0035 g/cm³

Answer:

17.5 Km

Explanation:

T = 3.5 hours

v = 5 K/hr

S = VT

S = 5 × 3.5

S = 17.5 Km

Answer:

299.83°K

Explanation:

So, kelvin is a means of measuring temperature, as the question implies. To convert Celsius, one form of measuring temperature, to Kelvin, another form of measuring temperature, we must know the conversion median. Our median is that 0°C = 273.15°K. So, now, as we know that 0°C = 273.15°K, 26.68°C = 273.15°K + 26.68°. Because 273.15K might as well be zero degrees celsius (according to our median 0°C = 273.15°K), we simply add 26.68° to 273.15K and get 299.83°K

Taking into account the reaction stoichiometry, the mass of silver(I) chloride formed is 930.37 grams.

In first place, the balanced reaction is:

2 AgNO₃ + BaCl₂ → 2 AgCl + Ba(NO₃)₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The molar mass of the compounds is:

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

AgNO₃: 2 moles ×169.87 g/mole= 339.74 grams

BaCl₂: 1 mole ×208.24 g/mole= 208.24 grams

AgCl: 2 moles ×143.32 g/mole= 286.64 grams

Ba(NO₃)₂: 1 mole×261.34 g/mole= 261.34 grams

The following rule of three can be applied:  if by reaction stoichiometry 208.24 grams of barium chloride form 286.64 grams of silver(I) chloride, 675.9 grams of barium chloride form how much mass of silver(I) chloride?

[tex]mass of silver(I) chloride=\frac{675.9 grams of barium chloride x286.64 grams of silver(I) chloride }{208.24 grams of barium chloride}[/tex]

mass of silver(I) chloride= 930.37 grams

Finally, the mass of silver(I) chloride formed is 930.37 grams.

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Carbon dioxide + Water Glucose (sugar) + Oxygen CO2 + H2O C6H12O6 + 6O2 Cellular respiration or aerobic respiration is a series of chemical reactions which begin with the reactants of sugar in the presence of oxygen to produce carbon dioxide and water as waste products.

Electrons in the Bohr model follow the number of elements in the rows of the periodic table.

2 in the first orbit

8 in the second and third ring

18 in the fourth etc...

The Bohr model is a simplistic means of explaining the placement of the subatomic particles of the elements of the periodic table.

The Bohr model arrangement of electrons follows the same pattern as the periodic table.

2 elements in the first row, and 2 electrons in the first orbit.

8 elements in the second row, and 8 electrons in the second orbit.

8 elements in the third row, and 8 electrons in the third orbit.

The fourth and fifth orbits would therefore hold 18 electrons.

For most chemists, the Bohr model does not work well beyond the third row of the periodic table because the model becomes quite oversized and bulky.

Answer:

C

Explanation:

four chiral centers

Answer:

64

Explanation:

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Answer:

c) oil and vinegar

Explanation:

A heterogeneous mixture is a mixture that does not have a "uniform composition" (meaning that the entire mixture is not thoroughly mixed to be the exact same. In different parts of the mixture, there is a              non-consistent / differing composition.)

Oil and vinegar, as you may know, do not thoroughly mix when put together--different parts of the mixture are made of different compositions. Some parts are made of oil, and some are a concentration of vinegar, but because they are not able to be mixed entirely, the mixture is considered a heterogeneous mixture. If you were to take different samples of different parts of the liquid, you would have a clear separation of oil and vinegar.

Milk is thoroughly milk--if you take out a tablespoon, it will be milk entirely--and it will have the same composition as all of the other milk in the bottle.

Air is complicated--and it can be described as either, but the question was likely intending the answer of oil and vinegar.

Vinegar and water do thoroughly mix. Vinegar absorbs water on a molecular level, so the mixture is thoroughly mixed when put together.

(Hope this helps!)

The balanced equation for this reaction is [tex]3\text{CO}+\text{Fe}_{2}\text{O}_{3} \longrightarrow 2\text{Fe}+3\text{CO}_{2}[/tex].

This means that for every mole of iron(III) oxide consumed, 3 moles of carbon monoxide are consumed.

This means that iron(III) oxide has a formula mass of 2(55.845)+3(15.999)=g/mol, and thus 318 g is equal to [tex]\frac{318}{159.687}=1.9913956677751 \text{ mol}[/tex].

So, this means we need [tex]3(1.9913956677751)=5.9741870033253 \text{ mol}[/tex] of CO.

This means CO has a formula mass of 12.011+15.999=28.01 g/mol, and thus 5.9741870033253 moles have a mass of (28.01)(5.9741870033253), which is equal to about 167 g (to 3 sf)