Comparing the data obtained online, the first group is more precise
The reason the above selection is correct is as follows;
Question: Parts of the question appear missing from a similar question online and included here;
First Group:
[tex]\begin{array}{|c|c|c|c|c|c|c|} Team \ a &Team \ b&Team \ c&Team \ d&Team \ e&Team \ f&Team \ g\\2.77 \ cm&2.60 \ cm&2.80 \ cm&2.65 \ cm&2.75 \ cm&2.65 \ cm& 2.68 \ cm\end{array}\right][/tex]
Second Group
[tex]\begin{array}{|c|c|c|c|c|c|c|} Team \ a &Team \ b&Team \ c&Team \ d&Team \ e&Team \ f&Team \ g\\2.70 \ cm&2.78 \ cm&2.62 \ cm&2.65 \ cm&2.75 \ cm&2.80 \ cm& 2.60 \ cm\end{array}\right][/tex]
Calculations for the first group:
The average = (2.77 + 2.60 + 2.80 + 2.65 + 2.75 + 2.65 + 2.68)/7 = 2.7
The range = 2.80 - 2.60 = 0.20
The approximate ± range of the average = ±0.2/2 = ±0.1
The precision of the first measurement is 2.7 ± 0.1 cm
Calculations for the second group:
The average = (2.70 + 2.78 + 2.62 + 2.65 + 2.75 + 2.80 + 2.60)/7 = 2.7
The range = 2.80 - 2.60 = 0.20
The approximate ± range from the average = ±0.2/2 = ±0.1
The range of values from the average is approximately ±0.1 cm
The precision of the first measurement is 2.7 ± 0.1 cm
Method to determine precision:
Precision is given by the finding the average deviation and the standard deviation as follows;
[tex]\mathbf{Average \ deviation} = \dfrac{\sum \left | x - \mu \right |}{n}[/tex]
[tex]\mathbf{Standard\ deviation} =\sqrt{\dfrac{\sum \left ( x - \mu \right )^2}{n}}[/tex]
Where;
μ = The mean or average = 2.7
n = The number of items (count) of the data = 7
For the first group, we have;
[tex]\mathbf{\dfrac{\sum \left | x - \mu \right |}{n}} = \dfrac{0.07 + 0.1 + 0.1 + 0.05 + 0.05 + 0.05 + 0.02 }{7} = \mathbf{0.062857}[/tex]
The average deviation of the first group = 0.062857
∑(x - μ)² ≈ 0.0328
[tex]\mathbf{The \ standard\ deviation} =\sqrt{\dfrac{0.0328}{7}} \approx \mathbf{0.068452}[/tex]
For the second group, we have;
[tex]\mathbf{\dfrac{\sum \left | x - \mu \right |}{n}} = \dfrac{0.0+ 0.08 + 0.08 + 0.05 + 0.05 + 0.1 + 0.1 }{7} = \mathbf{0.06571428571}[/tex]
∑(x - μ)² ≈ 0.0378
[tex]\mathbf{The \ standard\ deviation} =\sqrt{\dfrac{0.0378}{7}} \approx \mathbf{0.073485}[/tex]
By using the average deviation, and standard deviation values, the deviation of the second group is more than the first group and therefore the first group is more precise
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How many moles of water are in 1.23x10^18 water molecules?
in scientific notation
Answer:
1.23x10^24 atoms/6.022x10^23 atom/mol = 2.04 mol H20
Explanation:
Which statements describe density? Check all that apply.
Density is a chemical property of an object.
The density of an object is constant.
Density is a derived unit of measure.
Density is the sum of the mass and volume of an object.
The density of an object determines whether it will sink or float.
( pick multiple)
Answer:
density is the sum of the mass and volume of an object
Identify the products represented by letters A-F to complete each chemical equation, then write the net ionic equations for the reactions including the physical states of reactants and products. Use the standard enthalpies of formation to calculate the changes in the standard enthalpies of reaction.
a) NaOH(aq)+HCl(aq)⟶A(aq)+B(l)
A=
B=
Balanced net ionic equation:
Δ0rxn=
b) NaOH(aq)+NH4Cl(aq)⟶C(aq)+D(aq)+E(l)
C=
D=
E=
Balanced net ionic equation:
Δ0rxn=
c) HCl(aq)+NH3(aq)⟶F(l)
F=
Balanced net ionic equation:
Δ0rxn=
The product of a chemical reaction is what is remaining at the end of the reaction. The combination between reactant to form products can happen in a variety of ways including combination of ions in a solution to form new compounds
The correct compounds representing the variables and the net ionic equations are as follows:
a) A = NaCl
B = H₂O
Balanced net ionic equation: OH⁻(aq) + H⁺(aq) → H₂O (l)
ΔHrxn = Negative
b) C = NH₃
D = NaCl(aq)
E = H₂O(l)
Balanced net ionic equation: OH⁻(aq) + NH₄⁺(aq) → NH₃(aq) + H₂O(l)
ΔHrxn = Negative
c) F = NH₄Cl(aq)
Balanced net ionic equation: H⁺(aq) + NH₃(aq) → NH₄⁺(aq)
ΔHrxn = Negative
The reason the above values are correct are as follows:
a) Part (i)
The given chemical equation is
NaOH(aq) + HCl(aq) → A(aq) + B(l)
The chemical equation is the reaction between sodium hydroxide NaOH (aq) and hydrochloric acid HCl (aq), the product of the reaction is sodium chloride and water as follows;
NaOH(aq) + HCl(aq) → NaCl(aq) + H₂O(l) + Heat
Therefore, we have;
A = NaCl, and B = H₂O
Part (ii)
The ionic equation is given as follows;
Na⁺(aq) + OH⁻(aq) + H⁺(aq) + Cl⁻(aq) → Na⁺(aq) + Cl⁻(aq) + H₂O (l)
Given that Na⁺(aq) and Cl⁻(aq) are spectator ions in the reaction, we have the balanced net ionic equation given as follows;
Balanced net ionic equation: OH⁻(aq) + H⁺(aq) → H₂O (l)
Part (iii)
ΔHrxn = Negative
b) Part (i)
The given chemical equation is NaOH(aq) + NH₄Cl(aq) → C(aq) + D(aq) + E(l)
The given reaction is between sodium hydroxide, NaOH(aq) and ammonium chloride, NH₄Cl(aq) and the products of the reaction are dissolved ammonia NH₃(aq), sodium chloride NaCl(aq), and water H₂O(l)
Therefore, we have;
NaOH(aq) + NH₄Cl(aq) → NH₃(aq) + NaCl (aq) + H₂O(l) + Heat
Therefore;
C = NH₃, D = NaCl(aq), E = H₂O(l)
Part (ii)
The ionic equation for the reaction is given as follows;
Na⁺(aq) + OH⁻(aq) + NH₄⁺(aq) + Cl⁻(aq) → NH₃(aq) + Na⁺(aq) + Cl⁻(aq) + H₂O(l)
The Na⁺(aq) and Cl⁻(aq) occur in both the reactants and products, therefore, they cancel out as spectator ions and we have;
Balanced net ionic equation: OH⁻(aq) + NH₄⁺(aq) → NH₃(aq) + H₂O(l)
Part (iii)
ΔHrxn = Negative
c) Part (i)
HCl(aq) + NH₃(aq) → F(l)
The given reaction is between hydrochloric acid and aqueous ammonia which has the product as ammonium chloride, NH₄Cl
Therefore, the reaction is given as follows;
HCl(aq) + NH₃(aq) → NH₄Cl(aq) + Heat
∴ F = NH₄Cl(aq)
Part (ii)
The ionic equation is given as follows;
H⁺(aq) + Cl⁻(aq) + NH₃(aq) → NH₄⁺(aq) + Cl⁻(aq)
Therefore, the chlorine ion Cl⁻(aq) occurs in both the reactant and product and can therefore, can be canceled out, and we have;
Balanced net ionic equation: H⁺(aq) + NH₃(aq) → NH₄⁺(aq)
Part (iii)
ΔHrxn = Negative
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which equation is used to calculate the free energy change of a reaction
Answer:
B bcx is a way of separating different crystals from each other and the other is a way of separating different crystals from each other and the other
5
Which of the following is true regarding the particle nature of a solid?
Particles in a solid -
A
move very little, so it cannot easily change its shape.
B
are relatively far apart, so it is highly compressible.
с
are in continual motion, and can slide past each other.
D
are very far apart, so it can easily change its shape.
Answer:
this answer is b no u can it very easy
Explanation:
because solid and liquid can compress easily
plz support me
Answer:
A. move very little, so it cannot easily change its shape.
How should you add metal to the graduated cylinder so that it will not crack the glass at the bottom?
Get the metal as close to thn
Answer:
you tilt the cylinder at a slight angle so that the metal slides down the sides, rather than drops all it`s weight to the bottom
The atomic number of the element with the maximum number of unpaired 2p electrons in the ground state is
1) 1 2) 7 3) 13 4) 8
If I have 4.9 moles of gas at a pressure of 2.0 atm and a temperature of 56 Celsius, what is the volume of the cantainer that the gas is
in? (R=0.0821 L*atm/mol*K)
Answer: 132 liters. or 130 liters with 2 sig figs.
Explanation: Use the ideal gas law: PV = nRT
We want V, so rewrite and plug in data:
Temperture must be in Kelvin (add 273.15 to
V = (nRT)/P
V = (4.9 moles)*(0.0821 L*atm/molK)*(328.2K)/(1atm)
V = 132 liters (3 sig figs). 130 liters with 2 sig figs
What are the missing coefficients for the chemical equation
[ ] C2H2 + [ ] O2 → [ ] CO2 + [ ] H2O
Answer:
2C2H2 + 5O2 → 4CO2 + 2H2O
Explanation:
Can someone please help me out !!!
Explanation:
Volume = FL - SL
= 39 - 33
= 6
Facts, figures, and other evidence learned through observation are call
Answer:
DataExplanation:
Data are the facts, figures, and other evidence gathered through observations.
Which TWO properties of water make it
essential for supporting the
development of life? (Again, there
are TWO answers here, be sure to check
both of them!
Water has all the ingredients needed to
create lite.
Water allows biomolecules (like proteins) to
move around and react with one another.
Life gets thirsty and needs to stay
hydrated.
EN
INTL
WS
Water helps regulate temperature so it
doesn't get too hot or too cold.
8
53
Answer:
oooooooooougifufofhhdykddykyd
PLEASE HELP ON EASY CHEMICAL PROPERTIES
Answer:
1, just I) color.
Explanation:
Physical properties are the properties that can be observed without changing the composition of a substance, such as color, temperature, density, and boiling point.
A physical change is a change in the substance that only modifies its aggregation state, such as solidification, and boiling.
Chemical properties are the properties that need a reaction to being observed, such as combustibility, which needs a combustion reaction to being quantified.
When a chemical reaction occurs, and the composition of the substance change, it's a chemical change.
So, heating copper with carbon is a chemical reaction, and purification by electrolysis is too. Color is the only physical property.
A sample of brass weighing 1.203g was analyzed. The zinc in the alloy was reacted with 35.123g of HCl in excess, according to the balanced equation:
Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)
After all the zinc reacted, the mass of the remaining solution weighed 36.309g
What was the mass of H2 produced?
What mass of Zn reacted?
What was the percentage of Zn (by mass) in the alloy?
The number of moles of reactants and products can be used to obtain the mass of products formed. The results obtained are as follows;
The mass of hydrogen produced is 0.0174 gramsThe mass of zinc produced is 0.5688 gramsThe percentage by mass of zinc in the brass alloy is 47.3 %The question says that HCl was in excess. It means that after the reaction, we will have unreacted HCl(aq) and ZnCl2(aq) in the remaining solution.
Hence;
Mass of ZnCl2(aq) formed = 36.309g - 35.123g = 1.186g
Number of moles ZnCl2(aq) formed = [tex]\frac{mass of ZnCl2(aq) formed}{molar mass of ZnCl2}[/tex]
[tex]\frac{1.186g}{136.286 g/mol}[/tex] = 0.0087 moles
From the reaction equation;
[tex]Zn (s) + 2HCl(aq) - > H2(g) + ZnCl2 (aq)[/tex]
To obtain the amount of Zn reacted
1 mole of Zn yields 1 mole of ZnCl2
x moles of Zn yields 0.0087 moles of ZnCl2
x = 0.0087 moles of Zn
a) 1 mole of Zn yields 1 mole of H2
0.0087 moles of Zn yields 0.0087 moles of H2
Mass of H2 = 0.0087 moles of H2 * 2 g/mol = 0.0174 grams
b)
Mass of Zn reacted = 0.0087 moles of Zn * 65.38 grams/mole = 0.5688 grams
c)
Percentage of Zn in the alloy = 0.5688 grams/1.203g * 100 = 47.3 %
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In the reaction 2H2 + O2 + H20, what coefficient should be placed in front of H2O to balance the reaction? 0 2 03 O 4
Answer:
2
Explanation:
2×2
2O
soooo
2H2O means 4H2O
This is a model of a water molecule which has two hydrogen atoms and one oxygen atom. Why ISN'T water considered to be a MIXTURE?
A.
Because the Hydrogen & Oxygen (or O & H) atoms bonded chemically
B.
Because the Hydrogen & Oxygen atoms are easily separated
A compound contains only carbon, hydrogen, and oxygen. Combustion of 8.544 mg of the compound yields 12.81 mg CO2 and 3.50 mg H2O. The molar mass of the compound is 176.1 g/mol. What are the empirical and molecular formulas of the compound
Answer:
The empirical formula is the formula with a minimum whole number ratio of the constituent atoms present in a molecule. While the molecular formula has the actual number of atoms of various elements present in the molecule of the substance.
Empirical formula is C₃H₄O₃
Molecular formula is C₆H₈O₆
This question involves finding the empirical and molecular formulas. Empirical formula is the one where minimum whole number ratio of the constituent atoms present in a molecule is shown whereas molecular formula is the one that shows the number of each type of atom that are present in a molecule.The compound contains only carbon, oxygen and hydrogen and undergoes combustion. Thus;[tex]C_{x}[/tex][tex]H_{y} O_{z}[/tex] + O₂ ⟶ xCO₂ + [tex]\frac{y}{z} H_{2} O[/tex]
The combustion yields 12.81 mg of CO₂.From online sources, molar mass of CO₂ = 44 g/mol
number of moles of CO₂ = 12.81/44 = 0.291m mol
Mass of carbon in it is; C = 12 × 0.291 = 3.492 mg
Similarly the combustion yields 3.50 mg H2O.molar mass of water = 18 g/mol
number of moles of water in it = 3.5/18 = 0.194m mol
Hydrogen has 2 nos in water and so;
number of moles of hydrogen = 2 × 0.194 = 0.388m mol
Mass of hydrogen = 1 × 0.388 = 0.388 mg
Compound is 8.544 mg and so;Oxygen mass = 8.544 - (3.492 + 0.388) = 4.664 mg
Similarly, moles of oxygen that has molar mass of 16 is;
no of moles of oxygen = 4.664/16 = 0.2915m mol
Thus;Ratio of C:H:O is; 0.291:0.388;0.2915
Simplifying this gives us the empirical formula ratio as;
3:4:3
Thus;
Empirical formula is C₃H₄O₃
Molar mass of C₃H₄O₃ = (12 × 3) + (1 × 4) + (16 × 3) = 88 g/molWe are told that the molar mass of the compound is 176.1 g/mol.
Thus;
Molecular formula is; (176.1/88)C₃H₄O₃ = C₆H₈O₆
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What volume of HCl must be used to prepare 350mL of 2.0M HCl solution using a stock solution containing 5L of 12.0M HCl?
Answer:
~58.3 mL
Explanation:
m1*v1=m2*v2 --> (12.0 M HCL) * v1 = 350mL * 2.0M HCL
--> 350*2.0 = 700
--> 700/12.0 M HCL = 58.3 mL repeating
• 1. An object has a mass of 570g and a volume of 2280ml. Calculate its
density. 250 kg/m3
Answer:
Density=mass/volume
= 570/2280
=0.25g/ml
1. Lanthanides and actinides are kept separately in the modern periodic table. Why?
2. Differentiate between long period and short period in any two points.
- Help!! Random / Plagiarised answers will be reported! *
Answer:
1.. Lanthanides and actinides are kept separately in the modern periodic table Why?
Lanthanides and actinides are kept separately in the modern periodic table because of following reason:
If they are placed in the body of the periodic table, the periodic table will become extremely long and hard to recognizemore scientific and technical reason why they chose to keep the lanthanides and actinides away from the rest of the periodic table was to help in the grouping of elements in blocksExplanation:
2. Differentiate between long period and short period in any two points.
Long period:
The 4th and 5th periods of the periodic table are called long periods. The long periods coontain 18 elements in themshort period:
The 2nd and 3rd periods of the periodic table are called short periods. The short periods contain 8 elements in themWhat is the Color of trioxonitrate(v)
Answer:
it's yellowish in color plz Mark me as brainliest
Answer:
It's a yellowish color like copper
please solve this fast
Answer:
b.troposphere
Explanation:
pls mark me brainliest
Can someone please help me
Answer:
white
Explanation:
Calculate the mass of a liquid with a density of 0.92g/ml and a volume of 15 ml
Answer:
13.8g
Explanation:
Remember that density is equal to mass over volume
d=m/v
rearrange the problem and you get dv=m
(0.92g/mL)(15mL)=13.8g
Animation shows a complete revolution of the Earth around the sun. What happens during this time? The moon makes one complete phase change. The moon makes one complete phase change. Four seasons occur on Earth. Four seasons occur on Earth. Earth experiences a complete day. Earth experiences a complete day. Day turns to night.
Answer:
Four seasons occur on Earth
Explanation:
When the Earth has completely one revolution around the Sun, then it has completed 1 year, and four seasons have occurred in the meantime.
Four seasons occur on Earth when the Earth completes a revolution around the Sun.
The following points can be considered:
The Moon makes one complete phase change when the Moon revolves around the Earth. The Moon makes one complete phase change by a month. Four seasons occur on Earth as a result of the Earth completes one revolution around the Sun. The Earth experiences a complete day as a result of the Earth’s rotation along its own axis. The day turns to night as a result of the Earth’s rotation along its own axis.Therefore the correct answer is Four seasons occur on Earth.
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sound travels at 331m/s. How long would it take for sound to travel across lake tahoe, which is 21.6 miles long
Answer:
It would take sound 104.998 seconds to travel across lake tahoe.
Explanation:
First let's convert the miles to meters, so, 21.6 miles = 34754.4 meters
Now, we will divide this number in meters by 331. So, 34754.4 / 331 = 104.998
And what will the unit be? Seconds will be the unit for time here so 104.998 seconds.
What do we call planets that are not in our solar system
Calculate the empirical formula of a compound that has a composition of 5.9% (by mass) hydrogen and 94.1% (by mass) oxygen.
Answer:
The empirical formula is the simplest form;
Given:
Oxygen O at 94.1% and
H at 5.9%
Assume 100grams.
94% = 0.941 x 100gm. = 94.1 gm x 1mole/16gm. = 5.88 moles of O
5.9% = 0.059 x 100gm. = 5.9gm. X 1moleH/1.002gm. = 5.88 moles of H
There is one mole of O for each mole of H so the empirical formula is [tex]O_1H_1[/tex]
and written as OH.
Explanation:
[tex]given \: that \: oxygen \: by \: 94.1\% (.941)\\ hydrogen \: by5.9\%(.059) \\ in \: 100gram \: \\ oxygen = 100 g\times .941 = 94.1 \times \frac{1(mol)}{16g} \\ = 5.88moles \: of \: oxygen \\ in \: hydrogen \: = .059\times 100 = 5.9 \times \frac{1mol}{1.002gram} \\ = 5.88mole \: of \: hydrogen \\ \: so \: here \: \: both \: oxygen \: andhydrogen = 5.88 \\their \: ratio = 1 \: 1 \\ so \: emparical \: formula = oh \\ thank \: you[/tex]
If you can run 6km in 24 minutes, how many cm can you run in 5 hours?
Answer:
7500000cm/hr
Explanation:
6km=600000cm
24min=24/60hr=0.4hr
so, according to the question
6k/24km=600000cm÷0.4hr
=1500000cm/hr
therefore in 5 hours we can run:
5×1500000cm/Hr
=7500000cm/hr
A person can run "7,500,000 cm" in 5 hours.
According to the question,
A person can run 6 km in 24 minutes, i.e.,
= [tex]\frac{6}{24} \ km/min[/tex]
and,
5 hours = 300 minutes
then,
→ A person can run in 5 hours:
= [tex]\frac{6}{24}\times 300[/tex]
= [tex]\frac{1800}{24}[/tex]
= [tex]75 \ km[/tex]
By converting km into cm, we get
= [tex]7500000 \ cm[/tex]
So the above is the right answer.
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What is 3 x 10^4 multiplied by 5 x 10^2?
Answer:
15000000
Explanation:
30000 x 500=15000000. I believe... lemme know if I was wrong, hope this helps <3.