How many atoms are in 5.70 x 10^32 mol of Rn?

Answer:

Copper iodide. I think

Answer:

hope it helps

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:

Higher than the actual value

Explanation:

Titration is a volumetric process in which a known volume of solution is dispensed from a burette to react with a known volume of solution in a conical flask.

When acid-base titration is carried out in such a way that the base is in the burette and the acid is in the conical flask and drops of the base adhere to the inner walls of the flask, but do not actually mix with the solution, the calculated acid concentration would be higher than the actual value.

This is because;

From CA= CBVBnA/VAnB

When VB(volume of base) that reacted is lower than the actual volume recorded, then the calculated volume of CA(concentration of acid) is much higher than the actual value since drops of the base adhere to the inner walls of the flask.

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:

Percentage of carbon:

[tex] { \tt{ = \frac{24}{30} \times 100\%}} \\ = 80\%[/tex]

Percentage of hydrogen:

[tex]{ \tt{ = \frac{6}{30} \times 100\%} } \\ = 20\%[/tex]

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:

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:

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:

True

Explanation:

The word Organic refers to the methods used to cultivate and process farm agricultural products. Organic foods are edible and nutritious substances consumed (both plants and animals) that are free from the use of synthetics and chemicals. In plants, the include the use of organic manure that serves as fertilizers and carrying out the weeding process by hand weeding. In animals, diseases can be prevented by maintaining a clean house or rotational grazing.

The benefit of organic foods are to produce food substances with no chemical substances.

Answer:

See explanation

Explanation:

First we divide the percentage by mass of each element by it's relative atomic mass then we divide the quotients obtained by the lowest ratio obtained in the first step.

C- 76.57/12, H= 6.43/1, O = 17.00/16

C- 6.38/1.06, H= 6.43/1.06, O= 1.06/1.06

C- 6, H- 6, O- 1

Empirical formula: C6H6O

[(12 ×6) + (6 × 1) + (16 × 1)]n=94.11

[72 + 6 +16]n = 94.11

n = 94.11/94

n= 1

Molecular formula = C6H6O

2)

C- 53.30/12, H- 11.19/1, O- 35.51/16

C- 4.44/2.22, H- 11.19/2.22, O- 2.22/2.22

C- 2, H- 5, O- 1

Empirical formula: C2H5O

[(2×12) + (5× 1) + (1×16)]n = 90.12

[24 + 5 + 16] n = 90.12

n= 90.12/45

n= 2

Molecular formula = C4H10O2

Answer:

-270.76°C

Explanation:

Given that metal Thallium becomes superconducting below the temperature of 2.39 kelvin i.e. this temperature is critical temperature for Thallium and below critical temperature a metal offers no resistance to the flow of electric current. Also the metal below its critical temperature expels the magnetic field in such a way that they do not penetrate the metal and pass through its surface only.

We have the relation between kelvin scale and degree Celsius scale of temperature measurement as:

[tex]C = K - 273.15[/tex]

[tex]C=2.39-273.15\\ C=-270.76^{o}C[/tex]

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.

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:

5.38 L

Option D.

Explanation:

2 NaOH(s) + 2 Al(s) + 6 H₂O(l)   →  2 NaAl(OH)₄(s)  + 3 H₂(g)

We convert mass of Al to moles:

4.32 g . 1 mol /26.98g = 0.160 moles

As NaOH is in excess, aluminum is the limiting reactant.

We see stoichiometry, were ratio is 2:3.

2 moles of Al can produce 3 moles of hydrogen

Our 0.160 moles may  produce (0.160 . 3)/2 = 0.240 moles of H₂.

We know that 1 mol of any gas at STP conditions is contained in 22.4L

So let's make the conversion factor:

0.240 mol . 22.4L / 1mol = 5.38 L

Answer:

–0.09

Explanation:

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

Measured value = 5.88 g

Actual value = 5.97 g

Error =?

The error in the student's measurement can be obtained as follow:

Error = Measured value – Actual value

Error = 5.88 – 5.97

Error = –0.09

Therefore, the error in the student's measurement is –0.09

Answer:

zero

Explanation:

I I think one should be so accurate with measurements and experiments

Answer:

The halogen is Iodine.

Explanation:

Using the ideal gas equation, we find the number of moles of gas present, n.

PV = nRT where P = pressure of gas = 1.41 atm, V = volume of gas = 109 mL = 0.109 L, n = number of moles of gas, R = molar gas constant = 0.082 L-atm/mol-K and T = temperature of gas = 398 K

Since PV = nRT, making n subject of the formula, we have

n = PV/RT

substituting the values of the variables into the equation, we have

n = 1.41 atm × 0.109 L/(0.082 L-atm/mol-K × 398 K)

n = 0.15369 atm-L/32.636 L-atm/mol

n = 0.0047 mol

Since n = m/M where m = mass of gas = 1.19 g and M = relative molecular mass of gas

So, M = m/n

M = 1.19 g/0.0047 mol

M = 252.7 g

Since halogens are diatomic the relative atomic mass is M/2 = 252.7g/2 = 126.34 g

From tables, the only halogen with this atomic mass is Iodine.

So, the halogen is Iodine.

Answer:

As either mass increases, the gravitational force between them

increases.

Explanation:

According to Newton's law of universal gravitation;

F α m1m2/r^2

That is, the force between two masses in a gravitational field is directly proportional to the product of the two masses and inversely proportional to their distance apart.

Hence, as either of the masses increase, the force of gravitation between the two masses increases. Hence the answer.

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:

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:

KBr dissolved in water.

Explanation:

A substance conducts electricity as a result of the presence of mobile ions in the substance.

An ionic substance such as KBr when dissolved in water releases free ions which become charge carriers in solution hence the solution conducts electricity. Solid ionic substances such as solid KBr and solid baking soda do not conduct electricity because the ions are strongly bound to each other in the crystal lattice.

Molecular substances such as sugar and alcohol do not conduct electricity even in solution.

Answer:

Changes of state occur at segment

✔ B–C

and segment

✔ D–E

Explanation:

got it right on edge :)

The amount of energy added to the ice between Point A and Point D is approximately 25 kJ.

To calculate the amount of energy added to the ice between Point A and Point D, we need to consider the different stages of the heating curve.

Heating the ice from -20°C to 0°C:

The energy required to raise the temperature of the ice can be calculated using the specific heat of ice (2.10 J/(g·°C)) and the mass of the ice (60.0 g). The temperature change is from -20°C to 0°C, which is a total of 20 degrees.

Energy = mass × specific heat × temperature change

Energy = 60.0 g × 2.10 J/(g·°C) × 20°C

Energy = 2520 J

Melting the ice at 0°C:

The energy required to melt the ice can be calculated using the latent heat of fusion of ice (333.4 J/g) and the mass of the ice (60.0 g).

Energy = mass × latent heat of fusion

Energy = 60.0 g × 333.4 J/g

Energy = 20,004 J

Heating the water from 0°C to 15°C:

The energy required to raise the temperature of the water can be calculated using the specific heat of water (4.18 J/(g·°C)) and the mass of the water (60.0 g). The temperature change is from 0°C to 15°C, which is a total of 15 degrees.

Energy = mass × specific heat × temperature change

Energy = 60.0 g × 4.18 J/(g·°C) × 15°C

Energy = 3753 J

The total energy added to the ice between Point A and Point D is the sum of the energy calculated in each step:

Total Energy = Energy (Heating ice) + Energy (Melting ice) + Energy (Heating water)

Total Energy = 2520 J + 20,004 J + 3753 J

Total Energy = 25,277 J

Converting this energy to kilojoules (kJ):

Total Energy = 25,277 J ÷ 1000

Total Energy = 25.277 kJ

Therefore, the amount of energy added to the ice between Point A and Point D is approximately 25 kJ.

To know more about energy

https://brainly.com/question/1932868

#SPJ2

Answer:

2.75M

Explanation:

Density = mass/volume

Density of glycerol (C3H8O3) at 15°C is given as 1.2656 g/mL.

Volume of glycerol at this same temperature before dissolving in water = 50mL

Hence, using Density = mass/volume

1.2656 = mass/50

mass = 1.2656g/mL × 50mL

mass = 63.28g

Molarity of solution = number of moles (n) ÷ volume (V)

Volume of glycerol dissolved in water = 250mL = 0.250L

number of moles = mass/molar mass

Molar mass of C3H8O3 = 12(3) + 1(8) + 16(3)

= 36 + 8 + 48

= 44 + 48

= 92g/mol

n = 63.28g ÷ 92g/mol

n = 0.688mol

* Molarity = n/V

Molarity = 0.688/0.250

Molarity = 2.75M

Answer:

what do you need help with

Answer:

acetaldehyde

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

Explanation:

Answer:

3.65 g of cyclohexene

Explanation:

Cyclohexanol + phosphoric acid ----> cyclohexene

The reaction is 1:1 hence the limiting reactant is phosphoric acid.

Hence,

1 mole of phosphoric acid yields 1 mole of cyclohexene

0.0444 moles of phosphoric acid yields 0.0444 moles of cyclohexene

Theoretical yield = number of moles of cyclohexene × molar mass of cyclohexene

Theoretical yield = 0.0444 moles of cyclohexene × 82.143 g/mol

Theoretical yield = 3.65 g of cyclohexene

Answer:

118.06 mL

Explanation:

The neutralization reaction between HBr (acid) and Ba(OH)₂ (base) is the following:

2HBr + Ba(OH)₂ → BaBr₂ + 2H₂O

According to the equation, 2 moles of HBr react with 1 mol Ba(OH)₂. Thus, at the equivalence point the moles of acid and base react completely:

2 moles HBr = 1 mol Ba(OH)₂

We can replace the moles by the product of the molar concentration (M) and volume (V):

2 x (M HBr) x (V HBr) = M Ba(OH)₂ x V Ba(OH)₂

Now, we introduce the data in the equation to calculate the volume in mL of Ba(OH)₂:

V Ba(OH)₂ = (2 x (M HBr) x (V HBr))/M Ba(OH)₂

                 = (2 x 0.311 M x 57.7 mL)/(0.304 M)

                 = 118.06 mL

Therefore, 118 mL of Ba(OH)₂ are needed.

Answer:

mineral oil; close to; slowly turn

Explanation:

Temperature can be defined as a measure of the degree of coldness or hotness of a physical object. It is measured with a thermometer and its units are Celsius (°C), Kelvin (K) and Fahrenheit (°F).

Generally, temperature measures the average kinetic energy of particles in a particular substance.

A thermometer can be defined as a device used for measuring the temperature (degree of hotness or coldness) of a body or substance is. It is a thin glass having a bulb on one of its end and typically contains either colored alcohol or mercury.

A thermometer adapter is used with a temperature probe in the distillation process, in order to determine readings.

To insert a thermometer into an adapter, use mineral oil to prepare or make suitable the thermometer. Then, hold the thermometer close to the adapter and slowly turn the thermometer into the adapter.