Answer:
Precision means that independent measurements are close to each other.
Accuracy means that independent measurements are close to a known or accepted value.
Explanation:
Accuracy refers to how close the measurements of a measurement system are to the true value while precision refers to how close the measurements are to each other. In other words, accuracy is the closeness of the value of one or more independent measurements to a true value, and precision is the closeness of two or more values of several measurements to each other.
Both are independent of each other, that is to say that the results in the values of a measurement can be precise and not exact, and vice versa.
So:
Precision means that independent measurements are close to each other.
Accuracy means that independent measurements are close to a known or accepted value.
convert 6.8 × 10^2 to standard notation.
Answer:
680
Explanation:
Move the decimal 2 to the right.
When a number is written using only the digits of the number, that is considered standard notation. 6.8 × 10² is converted into standard notation by shifting two decimal to the right side, then it became 680.
What is standard notation ?A form of writing a certain number, an equation, or an expression in a way that adheres to set norms is known as a standard notation. For instance, 4,500,000,000 years is how 4.5 billion years is written.
When a number is written using only the digits of the number, that is considered standard notation. Since words are not used in conventional number notation, this is the way that numbers are typically written.
The stages to writing a number in its standard form are as follows: Write the first digit of the supplied number in step one. Step 2: After the first number, add the decimal point. Step 3: Next, count how many digits there are in the supplied number after the first one and express that number as a power of 10.
Thus, the standard notation is 680.
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If you know the force applied to an object and measure its acceleration, which equation would you use to calculate the object’s mass? m = Fa m = a F m = a/F m = F/a
Answer: m=F/a
Explanation:
Answer:
d
Explanation:
hey can anyone help me with organic chemestry?
How does the government control scientific research?
O A. Scientists are dependent upon the government to set ethical
standards.
B. The government can take away money if a scientist is not
following ethical standards.
O C. The government determines which experiments are important.
D. Scientists can do only research that the government supports.
Answer: B) The government can take away money if a scientist is not following ethical standards
Explanation: hope this helped :)
The government control scientific research by taking away money if a scientist is not following ethical standards. Therefore, the correct option is option B.
While it is crucial to recognise that the government's role in scientific research is varied and extends beyond the control of ethical standards, funding agencies and institutions frequently require researchers to follow particular ethical norms and standards when conducting scientific investigations. Failure to adhere to these ethical norms may result in the loss or denial of research funding.
However, it is critical to recognise that the government's role in scientific research extends beyond simply enforcing ethical norms. Governments can also fund and support specific research areas or priorities, create regulations and guidelines for research practises, encourage researcher collaboration, provide infrastructure and resources, and establish policies that shape the overall direction and focus of scientific research.
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Is burning sugar a chemical or physical change? Please provide explanation
Answer:
It is a chemical change
Explanation:
the reason is because the will not be able to materialize back into it's original form.
Calculate the mass in grams of 8.35 × 1022 molecules of CBr4.
Answer: 45.983 g CBr₄
Explanation:
To convert from moles to grams, you know that we will need molar mass and Avogadro's number.
Avogadro's number: 6.022×10²³ molecules/mol
Molar mass: 331.627 grams/mol
Now that we have what we need, you can use these to solve for grams. [tex]8.35*10^2^2molecules CBr_{4} *\frac{1mol}{6.022*10^2^3molecules} *\frac{331.627 g}{1 mol} =45.983 g[/tex]
Our final answer is 45.983 g CBr₄.
I need help ASAP!! Plzz
Answer:
0.1
tenth
hundredth (0.01)
1.05 (can be anywhere from 1.00 to 1.10)
11.42 (can be anywhere from 11.40 to 11.50)
yes, it falls within reasonable doubt
You are comparing a reaction that produces a chemical
change and one that produces a physical change. What
evidence could you use to determine which type of
change is occurring?
If the reaction is a chemical change, new substances with different properties and identities are formed. This may be indicated by the production of an odor, a change in color or energy, or the formation of a solid.
Suppose now that you wanted to determine the density of a small crystal to confirm that it is graphite. From the literature, you know that graphite has a density of 2.25 g/cm^3. How would you prepare 20.0 mL of the liquid mixture having that density from pure samples of CHCl3 (d = 1.492 g/mL) and CHBr3 (d = 2.890 g/mL)? (Note: 1 mL = 1 cm^3.)
Answer:
The volume of first and second compound are 9.15 ml and 10.85 ml.
Explanation:
Given that,
Density of graphite = 2.25 g/cm³
Volume of mixture = 20.0 mL
Density of first compound = 1.492 g/ml
Density of second compound = 2.890 g/ml
Let the volume of first mixture = x
The volume of second mixture = (20-x)....(I)
We need to calculate the volume of first compound
Using formula of density of mixture
[tex]\rho=\dfrac{V_{1}\rho_{1}+V_{2}\rho_{2}}{V_{1}+V_{2}}[/tex]
Where, [tex]V_{1}[/tex] = volume of first compound
[tex]V_{2}[/tex] = volume of second compound
[tex]\rho_{1}[/tex] =density of first compound
[tex]\rho_{1}[/tex] = density of first compound
Put the volume into the formula
[tex]2.25=\dfrac{x\times1.492+(20-x)\times2.890}{x+20-x}[/tex]
[tex]45=1.492x+57.8-2.890x[/tex]
[tex]45-57.8=1.492x-2.890x[/tex]
[tex]12.8=1.398x[/tex]
[tex]x=\dfrac{12.8}{1.398}[/tex]
[tex]x=9.15\ ml[/tex]
We need to calculate the volume of second compound
Using equation (I)
[tex]V_{2}=20-x[/tex]
Put the value of x
[tex]V_{2}=20-9.15[/tex]
[tex]V_{2}=10.85\ ml[/tex]
Hence, The volume of first and second compound are 9.15 ml and 10.85 ml.
Can someone please help me with these questions!!!!!!
Answer:
1. A. 10°C
2. A. Boiling point
3. A. Less than liquids.
Explanation:
which of these substances are most likely crystalline solids?
Answer:
diamond
sugar
rubber
salt (NaCl)
wood
ice
flour
Answer:
diamond
sugar
salt
ice
Explanation:
How would replacing many amino groups with carboxyl groups change the properties of the compound?
Answer:
This replacements will make the compound less basic and more acidic
Explanation:
Replacing amino groups (-NH₂) which act as bases [because of there ability to accept hydrogen ion (H⁺)] with carboxyl group (-COOH) which acts as acid [because of it's ability to donate hydrogen ion (H⁺)] in a compound changes the property of the compound to be less basic and more acidic.
Monobromination of toluene gives a mixture of three bromotoluene products. Draw and name them.
Answer:
o-bromotoluene, m-bromotoluene and p-bromotoluene.
Explanation:
Hello,
In this case, on the attached picture you will find the reaction which yields o-bromotoluene as the first product, m-bromotoluene as the second product and p-bromotoluene as the last one since the substitution could be done at the second (ortho), third (meta) or fourth (para) carbons on the toluene.
Regards.
Which statement is false? a) When reactants become products, they do so through an intermediate transition state. b) At equilibrium, equal amounts of products and reactants are present. c) Most biocatalysts are proteins. d) AG is a function of Keq
Answer:
b) At equilibrium, equal amounts of products and reactants are present.
Explanation:
At equilibrium , the ratio of product of concentration of products and product of concentration of reactants is constant .
A + B ⇄ C + D
[C] [ D] / [ A ] [ B ] = Constant
So, the statement ( b ) is false .
All other statements are true .
What is the maximum length of a polyethene chain with molar mass 10^6 and monomer length 2.5?
Answer:
L=7.0125*10^-5
Explanation:
LET
Length of polyethene chain= L
Molecular weight OF polyethene= MW
Molecular weight of monomer =mw
Monomer length= l
L=(MW/mw) *l
L= (28.05g/mol10^6gmol-1) * 2.5
L=70.125*10^-6
L=7.0125*10^-5
Hence, the length will be L=7.0125*10^-5 .
To prepare 100.0 mL of a 0.0525 M solution of NaCl in water, what mass of sodium chloride is needed? The
molar mass of NaCl is 58.44 g/mol.
Answer:
0.307 g
Explanation:
Step 1: Given data
Volume of solution: 100.0 mL
Molarity of the NaCl solution: 0.0525 M
Molar mass of NaCl: 58.44 g/mol
Step 2: Calculate the moles of NaCl required
The molarity is equal to the moles of solute (NaCl) divided by the liters of solution.
M = moles of NaCl / liters of solution
moles of NaCl = M × liters of solution
moles of NaCl = 0.0525 mol/L × 0.1000 L = 5.25 × 10⁻³ mol
Step 3: Calculate the mass corresponding to 5.25 × 10⁻³ moles of NaCl
5.25 × 10⁻³ mol × 58.44 g/mol = 0.307 g
Ocean water becomes colder; the density of ocean water increases or decreases?
Answer:
.............increases
What is the A# of fluoride-19?
Answer:
atomic number of fluorine
is 9
The stock solution is 100 μM the protocol calls for 10 mL solution of 80, 60, 40 and 20 μM. Compute the table.Target Concentration(μM) Volume of stock(mL) Volume of water(mL)20406080
Answer:
See the answer below
Explanation:
Using the dilution equation:
m1v1 = m2v2
m1 =100 μM, v1 = ?, v2 = 10 mL
In order to prepare 80 μM, then m2 = 80 μM
v1 = [tex]\frac{80*10}{100}[/tex] = 8 mL
In order to prepare 60 μM
v1 = [tex]\frac{60*10}{100}[/tex] = 6 mL
In order to prepare 40 μM
v1 = [tex]\frac{40*10}{100}[/tex] = 4 mL
In order to prepare 20 μM
v1 = [tex]\frac{20*10}{100}[/tex] = 2 mL
Since the final solution has to be up to the 10 mL mark, the complete table would be:
Target Concentration(μM) Volume of stock(mL) Volume of water(mL)
20 2 8
40 4 6
60 6 4
80 8 2
The diameter of an atom is approximately 1 * 10 ^ - 10 * m . What is the diameter in decimeters?
Answer:
[tex]d=1x10^{-9}dm[/tex]
Explanation:
Hello,
In this case, considering that 1 m equals 10 dm, the required diameter of the atom in decimetres is:
[tex]d=1x10^{-10}m*\frac{10dm}{1m} \\\\d=1x10^{-9}dm[/tex]
Best regards.
How is it possible for water to be polar but uncharged?
For the following, identify the most likely value for x.a. BHx b. CHx c. NHx d. CH2Clx
Given :
a. [tex]BH_x[/tex] b. [tex]CH_x[/tex] c. [tex]NH_x[/tex] d. [tex]CH_2Cl_x[/tex] .
To Find :
Find the most likely vale of x for each one .
Solution :
a . [tex]BH_x[/tex]
Because boron have valency of 3 .
So , x = 3 .
b . [tex]CH_x[/tex]
Valency of carbon is 4 .
x = 4 .
c . [tex]NH_x[/tex]
Valency of nitrogen is 3 .
Therefore , x = 3 .
d . [tex]CH_2Cl_x[/tex]
Now ,we know valency of carbon is 4 and hydrogen is 1 .
Also , two hydrogen are already there .
So , only 2 electrons left to share .
Since , chlorine have valency of 1 .
Therefore , only 2 electrons of chlorine can connect .
x = 2 .
Hence , this is the required solution .
Eric's father asked an engineer to survey the field behind their house. He wanted to plant some apple and pear trees there. According to the survey, the field is 38 meters (m) long and 17 meters (m) wide. What is the perimeter of the field in centimeters?
Answer:
P=110 m
Explanation:
Length of the field is 38 m
Breadth of the field is 17 m
We need to find the perimeter of this field. It is in the form of a rectangle. The perimeter of a rectangle is given by :
P=2(l+b)
P=2(38+17)
P=110 m
So, the perimeter of this field is 110 m.
Enter a balanced equation for the reaction between aqueous lead (II) nitrite and aqueous lithium chloride to form solid lead (II) chloride and aqueous lithium nitrite.
Answer:
Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)
Explanation:
Let's consider the reaction between aqueous lead (II) nitrite and aqueous lithium chloride to form solid lead (II) chloride and aqueous lithium nitrite.
Pb(NO₂)₂(aq) + LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)
This is a double displacement reaction. We will start balancing Cl by multiplying LiCl by 2.
Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)
Now, we have to balance Li by multiplying LiNO₂ by 2.
Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)
The equation is now balanced.
The balanced chemical reaction equation required is; Pb(NO2)2(aq) + 2 LiCl(aq) -----> PbCl2(s) + 2LiNO2(aq)
In order to write a balanced chemical reaction equation, we must write down the symbols of the compounds involved as follows;
lead (II) nitrite - Pb(NO2)2
lithium chloride - LiCl
lead (II) chloride - PbCl2
lithium nitrite - LiNO2
Recall that the principle of writing a balanced chemical reaction equation is that the number of atoms of each element on both sides of the reaction equation must be the same. The required balanced chemical reaction equation is;
Pb(NO2)2(aq) + 2 LiCl(aq) -----> PbCl2(s) + 2LiNO2(aq)
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How many different elements occur naturally?
Answer:
94 are naturally made on earth
Explanation:
Answer:
94 or 98, i think.
Explanation:
A car drives on a road at a constant speed of 50 miles/hour.
The forward force of the car is ________________
the opposing friction and air
resistance forces.
The forward force of the car and the opposing friction and air resistance forces are ____________
( !!
Answer:
It will take the police car 3.5 hours to travel a distance of 175 miles traveling at a rate of 50 miles/hour.
Explanation:
the weight of a sack potato in india is 50kgf. will the weight increase or decrease in bhutan. why
Answer:
Assume that the sack was initially close to the sea level. Its weight will increase even though its mass stays the same.
Explanation:
The weight of an object typically refers to the size of the planet's gravitational attraction (a force) on this object. That's not the same as the mass of the object. The weight of an object at a position depends on the size of the gravitational field there; on the other hand, the mass of the object is supposed to be same regardless of the location- as long as the object stays intact.
Let [tex]g[/tex] denote the strength of the gravitational field at a certain point. If the mass of an object is [tex]m[/tex], its weight at that point will be [tex]m \cdot g[/tex].
Indeed, [tex]g \approx 9.81\; \rm N \cdot kg^{-1}[/tex] on many places of the earth. However, this value is accurate only near the sea level. The equation for universal gravitation is a more general way for finding the strength of the gravitational field at an arbitrary height. Let [tex]G[/tex] denote the constant of universal gravitation, and let [tex]M[/tex] denote the mass of the earth. At a distance [tex]r[/tex] from the center of the earth (where
[tex]\displaystyle g \approx \frac{G \cdot M}{r^2}[/tex].
The elevation of many places in Bhutan are significantly higher than that of many places in India. Therefore, a sack of potato in Bhutan will likely be further away from the center of the earth (larger [tex]r[/tex]) compared to a sack of potato in India.
Note, that in the approximation, the value of [tex]g[/tex] is (approximately, because the earth isn't perfectly spherical) inversely proportional to the distance from the center of the planet. The gravitational field strength
On the other hand, the weight of an object of fixed mass is proportional to the gravitational field strength. Therefore, the same bag of potatoes will have a smaller weight at most places in Bhutan compared to most places in India.
What is the density of a silver coin from the following data:
Mass of silver coin 6.581 g
Volume of coin and water 23.7 mL
Volume of water alone 23.1 mL
The answer is assumed to be in g/mL. Please type a numeric value only.
Answer:
you can use math wa, it helps
Can someone please help me w these chemistry conversion? 1. The density of Mercury is 13.6 g/mL. What is the volume of mercury, in quarts has a mass of 95.0 ounces? 2. Tetrachloroethylene, also called PERC, has a density of 1.62 g/mL. It was formerly used as a dry cleaning solvent. What is the mass in pounds of PERC contained in a 55.0 gallon drum? 3. Osmium is the most dense element having a density of 22.5 g/cm^3 Calculate the density of osmium in kg/m^3. 4. The density of Iron is 7.50 g/cm^3. What is the mass, in pounds, of a cube of iron that measures 5.00 cm on a side? 5. Lead has a density of 10.5 g/cm^3. What is the diameter of a lead ball that has a mass of 500.0 g? Report answer in cm.
Answer:
1. 0.209quart
2. 743.6pounds
3. 22500kg/m^3
4. 2.07pounds
5. 4.50cm
Explanation:
Note that, these questions are related to density which can be calculated using the formula:
Density (p) = Mass (m) / Volume (v)
However, the units are different for each questions, hence, must be made the same
1. 1 ounce = 28.35 grams
95 ounces will be 95 × 28.35 = 2693.2g
Volume = mass/density
Volume of Mercury= 2693.2/13.6
Volume= 198ml
1 ml = 0.00106quart
198ml = 198 × 0.00106 = 0.209quart
2. 1 gallon = 3785.4ml
55 gallons = 55× 3785.4 = 208197ml
Mass = density × volume
Mass = 1.62 × 208197
Mass = 337,279.14g
1 pounds = 453.592 g
337279.14 g = 337279.14/453.592
Mass = 743.6pounds
3. 1g/cm^3 = 1000kg/m^3
Hence, a density of 22.5g/cm^3 will be 22.5 × 1000 = 22500kg/m^3
4. Volume of a cube of side 5cm each will be 5×5×5 = 125cm^3
Density = 7.50g/cm^3
Mass = Density×volume
Mass in grams = 7.50 × 125
Mass = 937.5grams
1 pound = 453.592 g
Therefore, 937.5g will be 937.5/453.592 = 2.07pounds.
5. Volume = Mass / density
Volume = 500/10.5
Volume = 47.62cm^3
Since a ball is spherical in shape, volume of a sphere (V) = 4/3πr^3
To find radius, we say;
47.62 = 1.33 × 3.142 × r^3
47.62 = 4.179 × r^3
r^3 = 47.62/4.179
r^3 = 11.395
r = 3√11.395
r = 2.25cm
To get diameter (d), we multiply the radius (r) by 2,
d = 2 × 2.25
d= 4.50cm
Draw structures for compounds that meet the following descriptions in proton NMR:a) C2H6O; one singletb) C3H7Cl; one doublet and one septetc) C4H8Cl2O; two tripletsd) C4H8O2; one singlet, one triplet, and one quartet
Answer:
The structures are shown in the attachments.
Explanation:
Please see the attachments below for the structures.
Explanation:
For the structure in (a)There is only one environment denoted as 'a'.
Using the (n+1) rule to determine the multiplicity, m
where is the number of neighboring Hydrogen, then
Since, n = 0, then
m = 0 + 1 = 1 (which means singlet)
Hence, one singlet
For the structure in (b)There are two environments denoted as 'a' and 'b'
For 'a' ; n = 6
Hence, m = n + 1
m = 6 + 1 = 7 (this means septet)
For 'b'; n = 1
then, m = n + 1
m = 1 + 1 = 2 (this means doublet)
Hence, one septet, one doublet
For the structure in (c)There are two environments denoted as 'a' and 'b'
For 'a' ; n = 2
then, m = n + 1
m = 2 + 1 = 3 (this means triplet)
For 'b' ; n = 2
then, m = n + 1
m = 2 + 1 = 3 (this means triplet)
Hence, two triplets
For the structure in (d)There are three environments denoted as 'a', 'b', and 'c'
For 'a' ; n = 0
Hence, m = n + 1
m = 0 + 1 = 1 (this means singlet)
For 'b' ; n = 3
then, m = n + 1
m = 3 + 1 = 4 (this means quartet)
For 'c' ; n = 2
then, m = n + 1
m = 2 + 1 = 3 (this means triplet)
Hence, one singlet, one triplet, and one quartet