2. You are tasked with calculating the average weight of kindergartners in a class of
21 students. Their weights range from a low of 40.5 lbs to a high of 58.6 lbs.
How many significant figures should be in the average that you find?

Answers

Answer 1
There should be 3 significant figures in the average that you find because there are three significant figures in the weights you are using to find an average.

Related Questions

The flask contains 10.0 mL of HCl and a few drops of phenolphthalein indicator. The buret contains 0.160 M NaOH. It requires 18.2 mL of the NaOH solution to reach the end point of the titration. A buret filled with a titrant is held above a graduated cylinder containing an analyte solution. What is the initial concentration of HCl

Answers

Answer:

Approximately [tex]0.291\; \rm M[/tex] (rounded to two significant figures.)

Explanation:

The unit of concentration [tex]\rm M[/tex] is the same as [tex]\rm mol \cdot L^{-1}[/tex] (moles per liter.) On the other hand, the volume of both the [tex]\rm NaOH[/tex] solution and the original [tex]\rm HCl[/tex] solution here are in milliliters. Convert these two volumes to liters:

[tex]V(\mathrm{NaOH}) = 18.2\; \rm mL = 18.2 \times 10^{-3}\; \rm L = 0.0182\; \rm L[/tex].[tex]V(\text{$\mathrm{HCl}$, original}) = 10.0\; \rm mL = 10.0\times 10^{-3}\; \rm L = 0.0100\; \rm L[/tex].

Calculate the number of moles of [tex]\rm NaOH[/tex] in that [tex]0.0182\; \rm L[/tex] of [tex]0.160\; \rm M[/tex] solution:

[tex]\begin{aligned} n(\mathrm{NaOH}) &= c(\mathrm{NaOH})\cdot V(\mathrm{NaOH})\\ &= 0.160\; \rm mol \cdot L^{-1} \times 0.0182\; \rm L \approx 0.00291\; \rm mol\end{aligned}[/tex].

[tex]\rm HCl[/tex] reacts with [tex]\rm NaOH[/tex] at a one-to-one ratio:

[tex]\rm HCl\; (aq) + NaOH\; (aq) \to NaCl\; (aq) + H_2O\; (l)[/tex].

Coefficient ratio:

[tex]\displaystyle \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} = 1[/tex].

In other words, one mole of [tex]\rm NaOH[/tex] would neutralize exactly one mole of [tex]\rm HCl[/tex]. In this titration, [tex]0.291\; \rm mol[/tex] of [tex]\rm NaOH\![/tex] was required. Therefore, the same amount of [tex]\rm HC[/tex] should be present in the original solution:

[tex]\begin{aligned}&n(\text{$\mathrm{HCl}$, original})\\ &= n(\mathrm{NaOH})\cdot \frac{n(\mathrm{HCl})}{n(\mathrm{NaOH})} \\ &\approx 0.00291\; \rm mol \times 1 = 0.00291\; \rm mol\end{aligned}[/tex].

Calculate the concentration of the original [tex]\rm HCl[/tex] solution:

[tex]\displaystyle c(\text{$\mathrm{HCl}$, original}) = \frac{n(\text{$\mathrm{HCl}$, original})}{V(\text{$\mathrm{HCl}$, original})} \approx \frac{0.00291\; \rm mol}{0.0100\; \rm L} \approx 0.291\; \rm M[/tex].

55:55

The MSDS for benzene indicates that it is a clear liquid that has a substantial vapor pressure. It has a health rating of

2, a fire rating of 3, and a reactivity rating of O. It is a cancer-causing agent.

Based on this information, which statement about benzene is accurate?

O Benzene readily reacts with moist air.

O Benzene explodes if the container is shaken.

O Benzene must be kept away from flames.

O Benzene must be stored under high pressure.

Answers

Answer:

Benzene must be kept away from flames.

Explanation:

Hello,

In this case since MSDS tables show the potential risks of chemical compounds, for benzene which which has a substantial vapor pressure and a fire rating of 3, which means that is highly flammable (very likely to get on fire), we conclude then that benzene must be kept away from flames due to its high risk. The other options are incorrect since it has 0 reactivity, it is nor fragile so it is not affected by shaking and it could be storage at standard pressures since it is a liquid at standard conditions as well.

Regards.

A cannonball made of iron has a volume of 110. cm3. What is the mass, in kilograms, of the cannonball?

Answers

Answer:

1 cubic centimeter (cu cm) = 0.001 kilogram (kg)

110cm³ =110*0.001=0.11kg

Explanation:

The volume has been the space occupied by the object and substances and uses the derived units. The mass of the iron ball with a volume of 110 cubic centimeters is 0.11kg.

What is volume?

Volume has been the three-dimensional space that an object has been using in space. The volume can be measured differently for the various states of matter in various units. Volume is the physical parameter to measure the states of matter.

The estimation of the volume can be given by density or mass and has been expressed by the various units like liters, milliliters, cubic meters, cubic centimeters, kiloliters, cubic decimeters, gallons, etc.

The unit cubic centimeter can be converted into kilogram (kg) as:

1 cubic centimeter = 0.001 kilogram

Given,

The volume of a cannonball made of iron = 110 cubic centimeters

The unit conversion from cubic centimeter to kg is shown as:

1 cubic centimeter = 0.001 kg

110 cubic centimeters = 0.11 Kg

Therefore, 0.11 kilogram is the mass of a cannonball made of iron.

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The value of ΔG°′ΔG°′ for the conversion of glucose-6-phosphate to fructose-6-phosphate (F6P) is +1.67 kJ/mol+1.67 kJ/mol . If the concentration of glucose-6-phosphate at equilibrium is 2.95 mM2.95 mM , what is the concentration of fructose-6-phosphate? Assume a temperature of 25.0°C25.0°C .

Answers

Answer:

The concentration of fructose-6-phosphate is 1.50x10⁻³M

Explanation:

Gibbs Free energy, ΔG°, is defined as:

ΔG° = -RTln K

Where ΔG° = 1670J/mol

R is gas constant = 8.314J/molK

T is absolute temperature (25°C + 273.15 = 298.15K)

Thus, equilibrium constant, k, is:

1670J/mol = -8.314J/molK* 298.15K ln K

-0.6737 = ln K

0.5098 = K

K of the reaction:

G6P ⇄ F6P

is:

K = 0.5098 = [F6P] / [G6P]

As [G6P] is 2.95x10⁻³M:

0.5098 = [F6P] / [2.95x10⁻³M]

[F6P] = 1.50x10⁻³M

The concentration of fructose-6-phosphate is 1.50x10⁻³M





The elements carbon, hydrogen, oxygen, and nitrogen make up which percentage of the human body?

Answers

Answer:

96%   Hope it helps

Explanation:

Roughly 96% of the mass of the human body is made up of just four elements: oxygen, carbon, hydrogen and nitrogen, with a lot of that in the form of water. The remaining 4% is a sparse sampling of the periodic table of elements.

To create increased pressure in the lungs which of the following muscles might be active? Mark all that apply. (A) External Intercostals (B) Internal Intercostals (C)Pectoralis major (D) Abdominal muscles (E) Diaphragm (F) Serratus anterior

Answers

Answer:

the diaphragm,the rib cage muscles and the abdominal muscles.

Explanation:

From a functional point of view, there are three groups of respiratory muscles: the diaphragm, the rib cage muscles and the abdominal muscles. Each group acts on the chest wall and its compartments, i.e. the lung-apposed rib cage, the diaphragm-apposed rib cage and the abdomen.

what ahppens when you free lava?

Answers

Not very well explained question so my simple answer has to be, it spreads out and can burn a lot of things

Answer:

It will melt everything and if lava goes into water it will become rock.

Hope this helped you!

Explanation:

Which of the following is a savanna? a. Veldts b. Plains c. Steppes d. Llanos

Answers

Answer:

d) Llanos

Explanation:

Answer:

D . Llanos

Explanation:

Which statement correctly defines pasteurization?​

Answers

Answer:

Pasteurization is the process by which liquids are heated to kill bacteria that may be present.

explanation I got the correct answer

Answer:

Pasteurization is the process by which liquids are heated to kill bacteria that may be present.

Explanation:

i just did that one

What property of matter is a
measure of the force of
gravity on an object?

Answers

Answer:

No matter where that object is in the vast universe, it will have the same mass. Weight, on the other hand, is a measure of how much gravitational force is exerted on an object.

An open-topped tub is filled completely to the top edge with solid ice. What will happen when the ice melts?


A)

The tub will overflow.

B)

In the process of melting, 9 percent of the water will be converted to water vapor.

C)

The level of the water will be lower than the edge of the tub.

D)

There will be no change in the level of the tub.

Answers

Answer:

d

Explanation:

Answer:

B

Explanation:

I can sort the way each object moves by

Answers

Answer:

By the way they move

Explanation:

hope this helps

In which of does the convection only occur in

A. Gases
B. Fluids
C. Liquids
D. Solids

Answers

Answer:

B. Fluids

I hope this helps!

Answer:

B

Explanation:

Convert .0027 CL to mL.

Answers

Answer:

0.027 ml

Explanation:

[tex]1\:cl = 10\:ml\\0.0027 \: cl = x\:ml[/tex]

Cross Multiply

[tex]x = 0.027 \:ml[/tex]

Imagine that you are developing a TLC plate, but you get distracted and forget to take the TLC plate out. Later, when you remove your TLC plate from the developing chamber, you notice that the solvent front has reached the top of the TLC plate. How will the Rf values from this TLC plate compare with those of a student who stopped developing their TLC plate before the solvent front reached the top of the plate

Answers

Answer:

The full form of TLC is Thin layer chromatography which is used in separating non volatile mixtures.

Explanation:

In the context, the Rf values could not be read properly or determined properly and accurately if the solvent front flows to the top of the plate. If the solvent reaches the plate's top, then the Rf values reading will be different from the TLC plate where the solvent did not reach the plate's top.

If the solvent front reaches the top, then it is not possible to accurately determine draw the line and to determine how far the spot went. And thus it would be difficult to solve the ratio as the plate would keep advancing or developing and also the compound spot keeps rising. As a result, spots reaches higher or rises than the normal rise but the solvent front does not change, it remains same. Thus, the Rf value would be completely off.

Help me please, i’d appreciate it a lot! thank you!❤️

Answers

Explanation:

think so it is useful and sufficient for your question

How many sig figs are there
5.00000008

Answers

Answer:

2 sig figs.

Explanation:

Sig Fig Rules:

Any non-zero digit is a significant figure.

Any zeros between 2 non-zero digits are significant figures.

Trailing zeros after the decimal are significant figures.

Explain how plastic can be both beneficial and detrimental at the same time.

Answers

Answer:

Detrimental- Toxic chemicals leach out of plastic and are found in the blood and tissue of nearly all of us. Exposure to them is linked to cancers, birth defects, impaired immunity, endocrine disruption and other ailments

Beneficial- Plastic packaging helps protect and preserve goods, while reducing weight in transportation,

why is a lot of energy needed to break covalent bonds

Answers

Answer:

The strength of a bond between two atoms increases as the number of electron pairs in the bond increases.

Explanation:

Please help asap!! Need help for problem #2.

Naturally occuring iron, contains 5.82% ^54Fe, 91.66% ^56Fe, 2.19% ^57Fe, and 0.33% ^58Fe. The reslective atomic masses are 53.940 amu, 55.935 amu, 56.935 amu and 57.933 amu. Calculate the average atmoic mass of iron. (show work)​

Answers

Answer:

55.56 amu

Explanation:

Let A, B, C and D represent the four isotopes of iron.

The following data were obtained from the question:

Isotope A (Fe-54):

Mass of A = 53.940 amu

Abundance (A%) = 5.82%

Isotope B (Fe-56):

Mass of B = 55.935 amu

Abundance (B%) = 91.66%

Isotope C (Fe-57):

Mass of C = 56.935 amu

Abundance (C%) = 2.19%

Isotope D (Fe-58):

Mass of D = 57.933 amu

Abundance (D%) = 0.33%

Average atomic mass =.?

The average atomic mass of the iron can obtained as follow:

Average atomic mass = [(mass of A × A%)/100] + [(mass of B × B%)/100] + [(mass of C × C%)/100] + [(mass of D × D%)/100]

Average atomic mass = [(53.940 × 5.82)/100] + [(55.935 × 91.66 )/100] + [(56.935 × 2.19)/100] + [(57.933 × 0.33)/100]

= 2.848 + 51.270 + 1.247 + 0.191

= 55.56 amu

Therefore, the average atomic mass of the iron is 55.56 amu

Draw the product formed when 2-butanol undergoes reaction with TsCl and Et3N. CH3C6H4SO2Cl.

Answers

Answer:

Explanation:

In organic chemistry, the reaction between 2-butanol with TsCl and Et3N is known as the tosylation of the alcohol hydroxyl group. Alcohol is being changed to tosylate by the use of tosyl chloride under the influence of a base. Tosylation of alcohol is an example of a nucleophilic substitution reaction. From the image attached below, we will see how the reaction between 2-butanol proceed into the product by using tosyl chloride and a base(Et3N).

b.) If the half-life of Carbon-14 is 5230 years and I start with 100 grams, how long will it take for the
Carbon-14 to decay to 3.125 grams?

Answers

Answer:

26150 years

Explanation:

First we need to determine the number of half lives -- not years -- it'll take for 100g (of any element) to decay to 3.125 g

First Half Life 100/2 = 50

Seconf Half Life 50/2 = 25

Third Half Life 25/2 = 12.5

Fourth Half Life 12.5/2 = 6.25

Fifth Half Life 6.25/2 = 3.125

So it'll take 5 half lives for 100g to decay to 3.125g.

If the Half Life of Carbon-14 is 5230 and it will take 5 half lives, to determine the number of years we just need to multiply 5*5230

5*5230 = 26150

This means that it will take 26150 years for 100g Carbon-14 to decay to 3.125g.

Hope this helps!

Which set of elements has 4 valence electrons?

Answers

Answer:

carbon group

All the carbon group atoms, having four valence electrons, form covalent bonds with nonmetal atoms; carbon and silicon cannot lose or gain electrons to form free ions, whereas germanium, tin, and lead do form metallic ions but only with two positive charges.

The set of elements that has 4 Valence electrons are the carbon group.

What are valence electrons?

Valence electrons are those electrons that are found at the outermost shell of an element that can go into formation of chemical bonds with another element on a chemical reaction.

The group 14 elements in the periodic table are known to have a four Valence electron on their outermost shell.

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or the solution containing Zn2+(aq), n is 2, so the MM/n ratio will be the molar mass of Zn divided by 2: MM/n = (65.39 g/mol) / 2 = 32.70 g/mol Compare this theoretical value with your experimental result. If the plating efficiency is significantly less than 1, say it is 0.55, how would the observed MM/n ratio compare to the theoretical value?

Answers

Answer:

MM/n will be less than the theoretical value

Explanation:

Provided that

The plating efficiency is proportional to the element weight

i.e.

[tex]\frac{Zn^2}{(aq)}[/tex]

That represents [tex]\frac{MM}{n\ value}[/tex]

So,

MM by N value is

= 65.39 g /mol ÷ 2

= 32.70 g/mol

Also, the experimental plating value is 0.55 that represents that it is much lesser than the normal value

So it would be concluded that the MM by N would be lower than the theoretical value

Question you have about rocks or minerals

Answers

What minerals do rocks have?


Do all rocks have minerals?


What is the hardest mineral?

What happens to the principle energy level number when moving from s to p sub levels

Answers

Answer:

The principal energy level remains the same

Explanation:

A principal energy level is one defines where electrons reside in an atom and that can contain one or more sub levels and have 2·n² number of electrons located in different sub levels within the energy level. Therefore, when moving up from s to p within the same principal energy level, the principal energy level does not change value.

Cuci
what is the formula?

Answers

Answer:

Copper(I) chloride, commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentrated hydrochloric acid. Impure samples appear green due to the presence of copper(II) chloride.

Explanation:

Please mark me brainliest


The formula for a compound containing sodium and oxide ions would contain... This
compound would have an overall ... charge.

Answers

Negative
Explaintion.

Answer:

Explanation:

the formula of the compound containing sodium and oxide ion is

NaOH the charge on sodium is partial positive and the charge on hydroxide ion is partial negative

another compound containing sodium and oxide ion is Na2O here the charge on sodium oxide is neutral

1) Chemistry is a (physical/biological) science?

Answers

Answer:

Explanation:

Biological.

I hope I helped you! :)

Identify the characteristics of a good recrystallization solvent. Select one or more: Dissolves a chemical sample well at high temperatures. Is not an organic liquid with a low boiling point. Does not dissolve a chemical sample well at low temperatures. Does not dissolve a chemical sample well at high temperatures. Dissolves a chemical sample well at low temperatures. g

Answers

Answer:

Dissolves a chemical sample well at high temperatures.

Does not dissolve a chemical sample well at low temperatures.

Explanation:

Recrystallization involves the dissolution of the solute in a solvent at high temperature. As the solution cools, it becomes saturated and the solute crystallizes out of the solution.

A good recrystallization solvent must only dissolve the solute at high temperature and must not dissolve it at low temperature. Hence, these are the two conditions required for any good recrystallization solvent.

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