Questions tagged [significant-figures]
For questions regarding the digits of a number used to express it to a particular degree of accuracy.
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Number of significant figures to use in reporting the concentration of the titrand in acid-base titration [closed]
If you perform an acid-base titration yourself, how do you determine the number of significant figures to use when reporting on the concentration of the titrand?
Assume you perform seven titration ...
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Should durations of time be considered to determine final significant figures of answer?
In preparation for AP Chemistry this upcoming semester I've been assigned a number of challenge problems. One of them is as following:
Suppose that polluted air has carbon monoxide $(\ce{CO})$ levels ...
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How do mathematical operations involving exact numbers affect significant figures? [duplicate]
I'm asking for assurance that I'm not making any mistakes because I can't find these rules explicitly stated in my textbook or elsewhere, but it seems to me that:
When multiplying/dividing a measured ...
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What's the purpose of significant figures in measurements?
I have read about significant figures in my chemistry and physics books, but none of them pointed out the significance of the significant figures.
Searching the Internet I found two possible answers: ...
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Significant figures in a calculation of atomic mass from isotopic abundance
I had this question:
Naturally occurring europium consists of two isotopes with a mass of 151 and 153. Europium-151 has an abundance of 48.030 and, and europium-153 has a natural abundance of 51.970. ...
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Is precision measured by significant digits in chemistry?
I was recently asked this question:
An experiment is done 3 times, with a different measuring tool used
for each time. The results of the experiment are 1.39, 0.9, and 1.0
(all centimeters). Which ...
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2
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I need help checking to see if the answer I got is correct answer [closed]
My professor says that the answer is 583.5g. I got 583.0330822g. She says to use her periodic table. Her periodic table says the mass of Ag: 107.87g, N: 14.01g, O: 16.00g, and S: 32.06g. Below is the ...
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Measuring instruments and significant figures
To start with, I am familiar with the rules that we have for sig-figs.
I have two chemistry books by different authors (One by McMurry and the other one by Nivaldo J Tro).
I was doing some casual ...
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How many significant figures should I report calculating volume concentrations? [closed]
Let's say a $\pu{300mL}$ solution of $\ce{CuCl_2}$ was diluted to $\pu{900mL}$. I am then asked to calculate the concentration of the new solution. My solution to the problem is as follows:
$$\begin{...
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Significant Figures for Exponents and Logs [closed]
What are the Sig Fig rules for exponents and logs. Ex. if I have 10^-3.83, or log(4.32) how should the answer be represented
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Significant figures and accuracy [closed]
A sample was weighed using two different balances. The results were $\pu{(a) 4.929 g and (b) 5.0 g}$. How would the mass of the sample be reported?
Method 1
$$ \text{Average of the values} =\frac{4....
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Which is more precise? 328.4 or 0.0008? [closed]
What is more precise? 328.4 or 0.0008?
I want to know if precision is based on the number of significant figures or the number of places past the decimal?
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Why do significant figure rules contradict each other? [duplicate]
So I came across a problem in my chemistry textbook that brought up another question. The problem had to do with calculating the mass% composition of chlorine in a certain molecule.
So to go about ...
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What is a reliable way of writing significant figures in multi-step problems? [closed]
I understand the sig fig rules that pertain to addition and multiplication problems, however, in multi-step problems, I have not been able to find a systematic approach to getting the right amount. ...
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Significant figures and uncertainty [closed]
A narrow-necked volumetric flask with a capacity of 200mL has an uncertainty of ±0.150mL so should the number of significant figures after the decimal point in my final answer be three or two?
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Division, multiplication, addition and subtraction of significant figures [closed]
$1.$After adding two or more numbers, the number of digits after the decimal in the result=Least no. of digits after the decimal in the numbers being added.
$2.$After multilplying two numbers, no. of ...
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Significant figures of the product [closed]
How is
$$\frac{8.925 − 8.904}{8.925} × 100 = 0.24?$$
When I solved I got
$$\frac{0.021}{8.925} × 100$$
Now it will have to be $2$ significant numbers $(0.021)$ time $1$ significant number $(100)$ ...
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2
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A sample must not contain more than 2% contaminants to be pure. Are there instances where 2.12% is ok?
I do not have any background in chemistry, I am asking this on behalf of someone else, twice translated, so I really hope it makes sense.
"A maximum of 2%" seems quite a clear specification, but ...
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How many sig figs should go after this calculation? [closed]
How many significant figures should be reported in the answer to the calculation (Assume all numbers are experimentally determined).
$\frac{12.501 \times 3.52}{0.0042}+6.044$
I tried to do this ...
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How to get a precise answer to a textbook precipitation problem?
This question concerns a textbook problem* on precipitation. Briefly, there are $2\cdot10^{-4}$ of Mn$^{2+}$ and Cu$^{2+}$ ions in a liter of solution with $0.003$ M HClO$_4$. This solution is then ...
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Significant Figures Calculations and Precise Instruments [closed]
I understand the rules for significant figures and how to read instruments, except for one thing.
I was told that our digital scale is particularly precise to the 1,000ths decimal place.
So in ...
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Significant figures in percent error calculation?
Consider a percent error calculation where the measured value has 1 significant figure (XmL), and the actual/true value has 3 significant figures (0.XXXmL). Typically I would think that the percent ...
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How do significant figures work on this computation?
This isn't a homework question although it may seem like one. We've never really discussed significant figures and it was just introduced to us when we were learning how to solve word problems ...
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Why should you round to proper significant figures after you complete a calculation rather than while doing the calculation?
In class, my teacher mentioned that you should complete a calculation without considering significant figures and then at the very end, round to the proper number of significant figures. Why couldn't ...
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Significant Figures
I recently did my first chemistry lab where we had to find the average mass of our aluminum cylinder. We were required to weigh and record its mass 3 times using an electric balance which gave us a ...
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Significant figures conflict [duplicate]
So I am asked to solve this question from Silberberg:
Use Appendix C to calculate $[\mathrm{H_2S}]$, $[\mathrm{HS}^-]$, $[\mathrm{S^{2-}}]$, $[\mathrm{H_30}^+]$, $\mathrm{pH}$, $[\mathrm{OH}^-]$, $\...
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AP Chemistry: Sig Figs Question
This is the official answer of a problem on the AP Chemistry 2009B Exam:
The answer has two sig figs, but I think it should have 4 sig figs. I was taught that your end answer should have as many sig ...
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How would I use significant figures to find the answer of these dimensional analysis questions? [closed]
In chemistry class, I have been given a set of dimensional analysis questions to answer. I'm not sure if the units factor into whether or not significant figures will need to be applied. I know that ...
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Am I Using the Correct Number of Significant Figures (Heat Problem)?
The question is:
A patient arrives in the emergency room with a burn caused by steam. Calculate the heat, in kilocalories, that is released when $\pu{18.0 g}$ of steam at $\pu{100 °C}$ hits the ...
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Is significant figure important for atomic radius calculations? [closed]
Is significant figure important for atomic radius calculations?
Calculate the radius of a vanadium atom, given that V has BCC crystal structure, a density of $\pu{5.96 g/cm^3}$, and an atomic ...
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Chemistry 101 - significant figures [closed]
So i had my first chemistry 101 exam and got 21/25 , but iam not sure about one question, it's about significant digits , can u guys check if my answer is true or false as shown in picture.
Thanks
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Decimal places vs significant figures
I was given an online assignment problem today. The answer was to be given to 2 decimal places. The answer I gave was $$P_2=0.06$$
This to me seems like 2 decimal places. However the answer was ...
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Does the multiplication and division significant figures rule apply to unit conversions as well?
My chemistry teacher told our class that answers to calculations that involve multiplication and division should be given to same number of significant figures as the factor, dividend or divisor with ...
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Uncertainty of Atomic Mass [closed]
How should the uncertainty of the atomic masses of elements be quoted?
E.g., Mg has an atomic mass of 24.31, what is that value's uncertainty?
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Converting units and sig figs (finding molarity)?
This may seem very basic, but I'm a little confused.
"What is the molarity of a solution 500 mL of which contains 0.500 moles of HCl?"
Being that 500 has one significant figure, would it be 500 mL = ...
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How many significant digits are appropriate when one or more digits are eliminated (during subtraction)?
Say, for example, $50.0-49.6=0.4$. Does this result have $1$ significant figure, or $3$ (as in the data: $50.0$ and $49.6$)?
Had it been $50.0-4.6$, it is understood that the answer is $45.4$, by ...
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What do final zeros to the right of decimal point indicate?
Final zeros to the right of the decimal point are considered significant. What do those zeros indicate and why are they significant? For example, in 2.000 there are four significant figures.
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Use of significant figures in addition and subtraction
My book mentions:
The proper use of significant figures in addition and subtraction involves a comparison of only the absolute uncertainties of numbers. This means that only as many digits are ...
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Ka relating to Dissociation of Weak acid and Water
I am studying $K_a$ currently and there is a passage in the book that doesn't appear to make sense.
It states that from the equation
$$\ce{HA <=> H+ + A-}$$
that $$K_a = \frac{[H^+][A^-]}{[...
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Percent error and significant figures?
For an elementary chemistry class percent error is calculated as:
[actual-experimental]/actual x 100% edit:bracket represents absolute value
So my question is if the experimental is close enough to ...
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How to solve a math expression with proper significant digits?
I've talked with my friend from chemistry about this question, and looked all over the internet for like hours now, and couldn't find anything that would help in my situation.
The problem is this:
$$...
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Significant figures in conversion factors?
Example: I have $\pu{64 cm^{3}}$ of milk. How much is that in gallons?
When I use the conversion factors $\frac{\pu{1 mL}}{\pu{1 cm^3}}$
$\frac{\pu{1L}}{\pu{1000 mL}}$ $\frac{\pu{1.0567 qt}}{\pu{1 L}}...
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Significant Figures Calculations
I am confused regarding significant figures. Consider "Calculate the volume of 2.8 kg of liquid with density of 1.11 g/cm^3"
Then,
Volume = 2.8 kg * (cm^3 / 1.11 g) = 2522.522 (where 522 is recurring)...
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Does the addition or multiplication rule have precedence deciding the significant figures in 5×5.364? [duplicate]
How many significant figures should be present in the answer of
$5\times 5.364$?
Addition rule: The result cannot have more digits to the right of the decimal point than either of the original ...
user23923
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When expressing a quantity, do the non-significant figures determine whether you round up the last significant figure?
I had thought that the non significant figures determined whether the least significant figure was to be rounded up. For example, given the number $9.1145$, if the number is to be expressed as three ...
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How to round significant figures correctly?
Calculate how many grams of p-nitrophenol are required to prepare $\pu{250 mL}$ of a $\pu{11 mM}$ solution. (Answer to 3 significant figures.)
I worked it out as
\begin{align}
\frac{250}{1000}\,\...
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Do all conversion factors have an infinite number of significant figures?
I believe conversion factors have an infinite number of significant figures. They should be exact values; but not all of them are, are they?
I looked at a pdf document (via the Internet Archive) and ...
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Using significant figures when measuring with an instrument with marks other than powers of ten
If an instrument does have markings that are powers of ten, then finding the precision of the instrument is easy. For example, if a graduated cylinder had markings for every $\pu{0.1 mL}$, or every $\...
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How determine the number of significant figures of a feet/inch system?
How many significant figures are there in $5~\mathrm{ft}\ 10~\mathrm{in}$.
I know that $5~\mathrm{ft}\ 10~\mathrm{in}= 5.8\bar{3}~\mathrm{ft}=70~\mathrm{in}$, so I am not sure exactly how much ...
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How to recognise the significant figures in given input values for the calculated output value?
If the transfer of $1~\mathrm{kJ}$ of energy to a quantity of water causes its temperature to rise $10~^\circ\mathrm{C}$, what is the mass of the water? I know how to do the math and everything but I'...
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