what are the methods used to determine the boiling point of a compound?​

Answer: [tex]10\mu L[/tex] of volume needs to be pipetted out in the test tube.

Explanation:

We are given:

Mass of BSA to be formed = [tex]5\mu g=0.005mg[/tex]      (Conversion factor: [tex]1mg=1000\mu g[/tex]

Volume of stock solution = [tex]200\mu L=0.2mL[/tex]    (Conversion factor: [tex]1mL=1000\mu L[/tex]

It is also given that for the mass of BSA is 0.5 g, the volume used up is 1 mL

In order to have, 0.005 g, the volume of stock solution needed will be = [tex]\frac{1mL}{0.5g}\times 0.005g=0.01mL=10\mu L[/tex]

Hence, [tex]10\mu L[/tex] of volume needs to be pipetted out in the test tube.

Answer:

Hydrogen and fluorine form only one bond while carbon forms four bonds to other atoms.

Explanation:

This question brings us to the idea of valency. Fluorine is univalent while carbon is tetravalent.

Univalent means that fluorine can only form one bond to hydrogen while carbon forms as much as four bonds because it is tetravalent.

Hence fluorine and hydrogen have only one peg while carbon has four.

Answer:

heat; temperature; surrounding; insulated.

Explanation:

A calorimeter can be defined as a scientific instrument or device designed and developed for measuring the heat involved in reactions or other processes, especially by taking the measurement of the temperature of the materials surrounding the process.

Basically, a calorimeter is insulated using materials with very high level of resistivity so as to prevent heat transfer to the outside of the device (calorimeter). Some of the components that make up a simple calorimeter are thermometer, an interior styrofoam cup, an exterior styrofoam cup, cover, etc.

Additionally, a calorie refers to the amount of heat required to raise the temperature of a gram of water by one degree Celsius (°C).

Answer:

The maximum mass of water that could be produced by the chemical reaction=0.441g

Explanation:

We are given that

Given mass of HBr=5.7 g

Given mass of sodium hydroxide=0.980 g

Molar mass of HBr=80.9 g/ Mole

Molar mass of NaOH=40 g/mole

Molar mass of H2O=18 g/mole

Reaction

[tex]HBr+NaOH\rightarrow H_2O+NaBr[/tex]

Number of moles=[tex]\frac{given\;mass}{molar\;mass}[/tex]

Using the formula

Number of moles of HBr=[tex]\frac{5.7}{80.9}=0.0705 moles[/tex]

Number of moles of NaOH=[tex]\frac{0.980}{40}=0.0245moles[/tex]

Hydrogen bromide is in a great excess and the amount of water produced.

Therefore,

Number of moles of water, n(H2O)=Number of moles of NaOH=0.0245moles

Now,

Mass of water=[tex]n(H_2O)\times Molar\;mass\;of\;water[/tex]

Mass of water=[tex]0.0245moles\times 18=0.441g[/tex]

Hence, the maximum mass of water that could be produced by the chemical reaction=0.441g

C. It can help us track how quickly element of the climate are changing

Answer:

A molecular mass is mass on the substance  and mole is a unit of substance such as atoms and electrons.

Explanation:

Molecular mass: A molecule's molecular mass is equal to the sum of all of the atoms' individual atomic masses. It establishes the molecular mass of a single unit.

Example:

Molecular mass of O2 = 32 atomic mass units

Mole: A mole is [tex]6.02214076 x 10^2^3[/tex]of any chemical unit, including atoms, molecules, ions, and others. Due to the large number of atoms, molecules, or other components that make up any material, the mole is a useful measure to utilize. The initial definition of the mole was the number of atoms in 12 grams of carbon-12.

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Answer: hello the experiment related to your question is missing but I will provide a more general answer within the scope of your  question

answer :

presence of Impurities

Explanation:

The melting point of the crystals as obtained in the experiment will be close to but below reference melting points and will also melt slower because of the presence of impurities in the compound

Impurities alter the melting and freezing points from ideal freezing and melting points of compounds

Answer:

Deductive reasoning

Answer:

c. CH3CH2CH(CH3)CHO

Explanation:

Hello there!

In this case, according to the process for the one-step oxidation of a primary alcohol with a moderately strong oxidizing agent like pyridinium chlorochromate (PCC), whereby an aldehyde is produced, we infer that the corresponding product will be 2-methylbutanal, which matches with the choice c. CH3CH2CH(CH3)CHO according to the following reaction:

[tex]CH_3CH_2CH(CH_3)CH_2OH\rightarrow CH_3CH_2CH(CH_3)COH[/tex]

Regards!

Answer:

Indicate how the concentration of each species in the chemical equation will change to reestablish equilibrium after reactant or product is added.

[tex]2CO(g) + O2(g) <=> 2CO2[/tex]

Explanation:

When the reactants concentration increases, then the equilibrium will shift towards products and when the concentration of products increases, then equilibrium will shift towards reactants.

So, increases in concentration of carbon monoxide (CO) shifts the equilibrium to favor the formation of carbondioxide.

Similarly increase in concentration of oxygen also favor the formation of product carbon dioxide.

Increase in concentration of CO2 favors the formation of CO and O2.

Decrease in product concentration also favors the formation of product.

Decrease in reactant concentration favors the formation of reactants only.

Answer:

2KMnO4(aq) + 16HCl(aq) ------> 2MnCl2(aq) + 2KCl(aq) + 8H2O(l) + 5Cl2(g)

Explanation:

Chlorine is a diatomic halogen gas known for its greenish-yellow colour. It has a pungent smell and is only moderately soluble in water.

It is a very reactive gas and is never found in free state in nature.

Chlorine can be prepared in the laboratory by oxidation of hydrochloric acid using KMnO4 as follows;

2KMnO4(aq) + 16HCl(aq) ------> 2MnCl2(aq) + 2KCl(aq) + 8H2O(l) + 5Cl2(g)

The set up does not need to be heated.

Answer:

3-hexanol

1 -butanol

2-pentanol

Explanation:

Let us recall that chromic acid or chromate are strong oxidizing agents. When they are oxidized, their colour changes from orange to green.

This shows a reduction in chromic acid or chromate. The reaction of chromic acid or chromate with a primary alcohol yields a carboxylic acid while reaction with a secondary substrate yields an alkanal.

Note that Tertiary alkyl halides are not be oxidized hence reactions involving a point where invitation carried along occur.

3-ethyl-3-pentanol is a tertiary alkyl halide hence it can not be oxidized.

Answer:

Explanation:

From the given reaction:

[tex]6Cl_{2(g)}+2Fe_2O_{3(s)} \to 4FeCl_{3(s)}+3O_2[/tex]

From the Gibbs Free Energy table at standard conditions, the value of each compound is as follows:

[tex]G_f^0 \ of \ Cl_2 = 0 \ KJ/mol[/tex]                       [tex]G_f^0 \ of \ Fe_2O_3 = -742.24 \ KJ/mol[/tex]

[tex]G_f^0 \ of \ Fe_2Cl_3 = -334.05 \ KJ/mol[/tex]      [tex]G_f^0 \ of \ O_2 = 0 \ KJ/mol[/tex]

Now, the standard Gibb's Free energy for the given reaction can be estimated as follows:

[tex]\mathtt{\Delta G^0 = (4 *G_f^0(FeCl_3) +3*G_f^0(O_2)) - (6*G_f^0 (Cl_2) +2*G_f^0(Fe_2O_3))}[/tex]

[tex]\mathtt{\Delta G^0 = (4 *(-334.05) +3*(0)) - (6(0) +2(-742.24))}[/tex]

[tex]\mathtt{\Delta G^0 = 148.28 \ kJ/mol}[/tex]

using the following formula:

[tex]\mathtt{\Delta G^0 =-RTIn K_{eq}}[/tex]

the equilibrium constant can  be determined as:

[tex]\mathtt{ In K_{eq} =\dfrac{\Delta G^0 }{-RT}}[/tex]

[tex]\mathtt{ In K_{eq} =\dfrac{148.28*10^3 J/mol }{-(8.314 \ J/k mol )*298 \ K}}[/tex]

[tex]\mathtt{ In K_{eq} =-59.85}[/tex]

[tex]\mathtt{ K_{eq} =e^{-59.85}}[/tex]

[tex]\mathtt{ K_{eq} =1.0*10^{-26}}[/tex] to 2 significant figures.

Answer:

All energy is made by the sun because without the sun there would be no humans to produce other energy

Explanation:

We use many different forms of energy here on earth, but here’s the thing: almost all of them originate with the sun, not just light and heat (thermal) energy! The law of conservation of energy says that energy can’t be created or destroyed, but can change its form. And that’s what happens with energy from the sun—it changes into lots of different forms:

Plants convert light energy from the sun into chemical energy (food) by the process of photosynthesis. Animals eat plants and use that same chemical energy for all their activities.

Heat energy from the sun causes changing weather patterns that produce wind. Wind turbines then convert wind power into electrical energy.

Hydroelectricity is electrical energy produced from moving water, and water flows because heat energy from the sun causes evaporation that keeps water moving through the water cycle.

Right now, much human activity uses energy from fossil fuels such as coal, oil, and natural gas. These energy sources are created over very long periods of time from decayed and fossilized living matter (animals and plants), and the energy in that living matter originally came from the sun through photosynthesis.

solar panel shows what is the ultimate source of energy

Answer:

HCl

Explanation:

I took the test :)

Out of the following compounds , HCl is an acid as it has hydrogen as the proton donor.

Acids are defined as substances which on dissociation yield H+ ions , and these substances are sour in taste.

According to the number of H+ ions which are generated on dissociation acids are classified as mono-protic , di-protic ,tri-protic and polyprotic  acids  depending on the number of protons which are liberated on dissociation.

Acids are widely used in industries  for  production of fertilizers, detergents  batteries and dyes.They are used in chemical industries for production of chemical compounds like salts which are produced by neutralization reactions.

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The correct question is: How many moles are in [tex]8.73 \times 10^{25}[/tex] atoms of boron.

Answer: There are 145 moles present in [tex]8.73 \times 10^{25}[/tex] atoms of boron.

Explanation:

According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] atoms present in one mole of every substance.

Hence, number of moles present in [tex]8.73 \times 10^{25}[/tex] atoms is calculated as follows.

[tex]Moles = \frac{8.73 \times 10^{25}}{6.022 \times 10^{23}}\\= 1.45 \times 10^{2}\\= 145 mol[/tex]

Thus, we can conclude that there are 145 moles present in [tex]8.73 \times 10^{25}[/tex] atoms of boron.

Answer:

acetaldehyde

When acetaldehyde is heated with Fehling's solution, a red precipitate is formed.

Explanation:

Answer:

C2H3O2

Explanation:

Empirical formula is defined as the simplest whole-number ratio of atoms present in a molecule. To solve this question we need to convert the percentage of each atom to moles using molar mass. With the moles of each atom we can find the ratio:

Moles C -Molar mass: 12.01g/mol-

40.68g * (1mol/12.01g) = 3.387 moles C

Moles H-Molar mass:1g/mol-:

5.12g * (1mol/1g) = 5.12 moles H

Moles O -Molar mass: 16g/mol-

54.19g * (1mol/16g) = 3.387 moles O

Ratio of atoms (Dividing in moles of C that are the lower number of moles):

C = 3.387 moles C / 3.387moles C = 1

H = 5.12moles H / 3.387moles C = 1.5

O = 3.387moles O / 3.387 moles C = 1

This ratio twice (To have only whole-numbers):

C = 2

H = 3

O = 2

Empirical formula of succinic acid:

Answer:

Pharmaceutical laboratory helps in devloping and conducting research, vaccines. Various kinds of drugs and chemical substances used and are produced at a Pharmaceutical laboratory.

The pharmaceutical laboratories performs with various hazardous substances that results in exposure to various chemicals, biological substances and radiation. To avoid any injury or infection labs need to maintain all safety measures.

Spillage and relaseing chemical substances can be lethal during transportaions by safety measures for heling in for manufacturing of such therapeutic agents spillage and avoid wastage.

Maintaining good safety standards in the pharmaceuticals laboratory will help promote the health of technicians and workers which in turn will increase productivity and attain positive outcomes.

Answer:

2.39x10⁻⁴ moles

Explanation:

As the problem asks us the number of moles of KIO₃ that were titrated, all that is required of us is to calculate how many moles of KIO₃ are there in 23.92 mL of a 0.0100 M solution (All moles in the samples are titrated).

We can do so by using the definition of molarity:

converting 23.92 mL ⇒ 23.92 / 1000 = 0.02392 L

Answer:

26.9 g

81%

Explanation:

The equation of the reaction is;

4 KO2(s) + 2 CO2(g) → 3 O2(g) + 2 K2CO3(s)

Number of moles of KO2= 27.9g/71.1 g/mol = 0.39 moles

4 moles of KO2 yields 2 moles of K2CO3

0.39 moles of KO2 yields 0.39 × 2/4 = 0.195 moles of K2CO3

Number of moles of CO2 = 57g/ 44.01 g/mol = 1.295 moles

2 moles of CO2 yields 2 moles of K2CO3

1.295 moles of CO2 yields 1.295 × 2/2 = 1.295 moles of K2CO3

Hence the limiting reactant is KO2

Theoretical yield = 0.195 moles of K2CO3 × 138.205 g/mol = 26.9 g

Percent yield = actual yield/theoretical yield × 100

Percent yield = 21.8/26.9 × 100

Percent yield = 81%

Answer:

the answer is D .................

Answer:

No mass of HCl could be left over by the chemical reaction because is the limting reactant and it is all consumed.

Explanation:

Our reactants are: HCl and NaOH

Products are: NaCl and H₂O

This is a neutralization reaction that can also be called an acid base reaction, an acid and a base react to produce water and a neutral salt, in this case where we have strong acid and base.

Ratio is 1:1. We convert mass to moles:

35 g . 1 mol / 36.45 g = 0.960 moles of HCl

73 g . 1 mol / 40 g = 1.82 moles of NaOH

As ratio is 1:1, for 0.960 moles of HCl we need 0.960 moles of NaOH and for 1.82 moles of NaOH, we need 1.82 moles of acid.

As we only have 0.960 moles of HCl and we need 1.82 moles, no acid remains after the reaction goes complete. HCl is the limiting reactant, so the acid, it is all consumed.

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Answer:

is this chem

Explanation:

Answer:

See explanation

Explanation:

Equation of the reaction;

Na2CO3(aq) + 2HCl(aq) -------> 2NaCl(aq) + H2O(l) + CO2(g)

Number of moles of Na2CO3 = 21.2g/106g/mol = 0.2 moles Na2CO3

Number of moles of HCl = 21.9g/36.5g/mol = 0.6 moles of HCl

1 mole of Na2CO3 reacts with 2 moles of HCl

0.2 moles of Na2CO3 reacts with 0.2 × 2/1 = 0.4 moles of HCl

Hence Na2CO3 is the limiting reactant

Since there is 0.6 moles of HCl present, the number of moles of excess reagent=

0.6 moles - 0.4 moles = 0.2 moles of HCl

1 mole of Na2CO3 forms 1 mole of water

0.2 moles of Na2CO3 forms 0.2 moles of water

Number of molecules of water formed = 0.2 moles × 6.02 × 10^23 = 1.2 × 10^23 molecules of water

1 mole of Na2CO3 yields 1 mole of CO2

0.2 moles of Na2CO3 yields 0.2 moles of CO2

1 mole of CO2 occupies 22.4 L

0.2 moles of CO2 occupies 0.2 × 22.4 = 4.48 L at STP

Hence;

V1=4.48 L

T1 = 273 K

P1= 760 mmHg

T2 = 27°C + 273 = 300 K

P2 = 760 mmHg

V2 =

P1V1/T1 = P2V2/T2

P1V1T2 = P2V2T1

V2 = P1V1T2/P2T1

V2 = 760 × 4.48 × 300/760 × 273

V2= 4.9 L

The limiting reactant is the reactant that determines the amount of product formed in a reaction. When the limiting reactant is exhausted, the reaction stops.

Answer:

The volume will be "2.95 L".

Explanation:

Given:

n = 0.104

p = 0.91 atm

T = 314 K

Now,

The Volume (V) will be:

= [tex]\frac{nRT}{P}[/tex]

By putting the values, we get

= [tex]\frac{0.104\times 0.0821\times 314}{0.91}[/tex]

= [tex]\frac{2.6810}{0.91}[/tex]

= [tex]2.95 \ L[/tex]

Answer:

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