Questions tagged [density]
For questions involving (theoretical or experimental) comparison of density of elements or substances, calculating density of solutions, effects of temperature on density, and other chemical aspects of density.
161
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meaning of ingredient labelling `w/v`
A mouthwash states it has among other ingredients, menthol 0.042% w/v. What is the correct interpretation?
This chemistry.stackexchange.com answer says it's weight per volume with unspecified units, ...
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1
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Density of unknown metal
An empty flask weighs $\pu{115.713 g}$. When filled water at $\pu{20 °C}$ it now weighs $\pu{365.263 g}$. The flask is then emptied and a $\pu{15.000 g}$ sample of unknown metal is added to it. It is ...
user136885
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1
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91
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At what temperature is bismuth the densest?
Both water and bismuth have denser liquids compared to solid forms, and we know water is the densest at the temperature of about 4°C.
Does the same thing apply to bismuth? Of course, I know the ...
user85778
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1
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Any way to predict what quantities of heptane and chloroform will match the density of water?
I am trying to make a solution of heptane and chloroform that matches the density of water.
Is this something which must be done experimentally as it is generally unpredictable? Does a software exist ...
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1
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Find the w/w percentage nitrogen in an ammonium nitrate solution
MCQ Question:
What is the w/w percentage of nitrogen (N) in an ammonium nitrate solution with a density of 1.05 g/cm3 and a molar concentration of 2.1 mol dm-3?
(a) 2.8 %
(b) 11.2 %
(c) 16.0 %
(d) 5.6 ...
- 91
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1
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63
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Identify two hydrocarbons using volume and density [closed]
Question:
A gaseous mixture with volume 16.8 dm3 contains two unsaturated neighboring hydrocarbons belonging to the same group. Density of the mixture was 14.4 times as hydrogen gas.
What could be ...
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2
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Density of dissolved and non-dissolved salts
I am doing a calculation, which needs to be 100% correct. My question is as follows; Does the density of dissolved salt differentiate from the density of non-dissolved salts?
My specific problem is a ...
Martin Sneltvedt
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145
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Find volume of methanol produced via reaction between carbon monoxide and hydrogen gases
Methanol is manufactured by the reaction of carbon monoxide gas with hydrogen gas. If a $95~\%$ yield is usually obtained, approximately how many liters of hydrogen gas at $\pu{350 °C}$ and $\pu{300 ...
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My experiemental density of H2 does not match the published data. What causes this discrpenecy?
I placed 1 gram of NaBH4 in a balloon and placed it over a glass round bottle filled with water and acetic acid. While secured, I emptied the balloon into the bottle and made sure to wash the inside ...
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1
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Is there any material that, subjected to electricity, extends in size in multiples without substantial change in heat for human use? [closed]
Is there any material that can molecularly restructure so as to expand its intra- or inter-molecular distance by no less than three-fold without substantially losing its structural integrity and ...
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Why the density of liquid decreases and density of vapour increases as we approach towards the critical state/point
Pressure and temperature have opposite effects on density. As temperature increases at constant pressure density decreases and as pressure increases at constant temperature the density increases (and ...
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What is the sample density used for a buoyancy mass correction?
For a lab exercise to calibrate volumetric glassware I was given the follow equation to correct weighings for the density of air:
$$m_\mathrm{c} = m_\mathrm{s}\,\frac{1 - \rho_\mathrm{a}/\rho_\mathrm{...
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1
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Additives to increase water density and solubility [closed]
What additives do I need to add to a water-based drink (coffee or tea for example), to increase its density and to make the drink insoluble (like olive oil for example) in salt sea water or inland ...
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IAPWS-IF97 empirical equations for water and steam
IAPWS-IF97 provides empirical equation the dynamic viscosity and the thermal conductivity for water, are there any formulas by IAPWS-IF97 for the density and the specific heat capacity of water?
I ...
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How do water vapor molecules push other air molecules away?
I've read that when water vapor enters the atmosphere, the vapor molecules push the oxygen and nitrogen molecules out of the way and occupy their space.
But if water vapor molecules are lighter than ...
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How molarity and mass fraction are related? [closed]
Concentrated sulfuric acid contains very little water, only $5\,\%$ by mass. It has a density of $\pu{1.84 g mL-1}$. What is the molarity of this acid?
I know to use the molarity $c$ is in $\pu{mol L^...
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Why is Molar Mass of a gas twice the vapour density?
I've seen this relation at a number of places, and I can't get why. A simple Google search doesn't give me a simple answer either.
Also, are there any exceptions/conditions for this relation to be ...
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COSMO Segment charge density via NWChem [closed]
I'm struggling to get COSMO segment surface charge densities that I need to create the sigma profiles in COSMO-SAC.
I am not a chemist by training, so please explain like I am five. I've read papers ...
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Why are certain gases with higher molar masses less dense than the ones that have a lower one?
Neon, despite having a larger molar mass than nitrogen, oxygen and fluorine, is less dense than all of them. This also goes that fluorine (again) and chlorine are both denser than argon, even though ...
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Can someone explain this answer in detail? [closed]
The density of iron is $\pu{7.874 g/cm3}$ and its unit cell volume is $\pu{2.364E-23 cm3}$. These values indicate that there are: two Fe atoms per unit cell and the metal is body-centered cubic.
I am ...
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Saturated vapor and liquid densities (VLC curve) from Helmholtz free energy equation of state
I have been reading about the statistical associating fluid theory (SAFT) which computes the Helmholtz free energy ($A$) from the SAFT EoS (a hell lot of equations) for a molecule of interest, and is ...
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Is the density of a mixture ever just the sum of the densities of each species in the mixture? [closed]
My current hypothesis is that this is true when the volume is finite and perhaps this would cause the densities to be additive.
For example, imagine there is a closed container, 2 L in size. And ...
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A dense solute for oils that's easy to acquire
I'm working on a crafts project that is basically putting oil, water and glue in a bottle together with glitter just so you look at it. I want to see how it looks if the density of the oil is very ...
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Current density from overpotential
A current of $190$ mA is measure for a $2.5$ cm$^2$ electrode in contact with a solution containing M$^{2+}$/M$^{3+}$ metal ions at room temperature at a overpotential of +$180$mV. The transfer ...
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Water density in the calculation of the ionic product of water
In 2019 the International Association for the Properties of Water and Steam released this document for the semi-empirical calculation of the ionization constant of water: http://www.iapws.org/relguide/...
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Compare density of halogen substituted benzene rings
The correct decreasing order of densities of the following compounds is :
(1) (D) > (C) > (B) > (A)
(2) (C) > (D) > (A) > (B)
(3) (C) > (B) > (A) > (D)
(4) (A) > (B) >...
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0
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Density and partial pressure [closed]
A sample of $\ce{NOBr}$ gas was placed in a rigid flask where it decomposes at $\pu{25 ^\circ C}$ according to the following reaction:
$$\ce{2NOBr(g) <=> 2NO(g) + Br2(g)}$$
At equilibrium, the ...
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0
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Heat released at constant pressure and temperature and heat released at constant density and temperature
Is there a relation between heat released at constant pressure and temperature and heat released at constant density and temperature?
I was reading some books on propulsion and combustion, and the ...
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Why is potassium less dense than sodium?
Potassium has a density of $\pu{0.86g/cm3}$ and sodium has a density of $\pu{0.97g/cm3}$,even though potassium is below sodium and one might expect the alkali metals to exhibit monotonously increasing ...
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Density and Viscosity for Solution: 80% Liquid Methane CH4 with Solution of 20% Gas Nitrogen N2 on Surface of Titan (the largest moon of Saturn)?
Problem:
Need to estimate the density and dynamic viscosity of such a mixed fluid: 80% Liquid Methane CH4 with solution of 20% Nitrogen Gas N2 with temperature of 94K and pressure of 1,467 hPa (the ...
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Relationship between molar mass and density in solids
In ideal gases, it's pretty clear that 1 mole of gas occupies 22.4 L at STP. By knowing this, it's easy to calculate density given molar mass. However, this isn't true for solids. If I know molar mass ...
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Why does a 57.15% ABV spirit (ethanol+water) have a density of 923 kg per cubic meter?
According to the UK proof standard, a 100 proof spirit was defined as a spirit with gravity of $\frac{12}{13}$ that of water or $\pu{923 kg m-3}$, which is equivalent to $\mathrm{57.15\% \ ABV}$.
One ...
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What factors other than atomic weight affect density of an element? [closed]
Iron, for example, has an atomic weight of 55.845
Whereas hydrogen's atomic weight is 1.008, 1.8% of Irons.
And the density of Hydrogen (at STP) is 0.0899 g/L, 1.14% of of Iron's density of 7.874 g/...
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1
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Air bubbles in water [closed]
Problem :
Gas. Density. (Composition)
N2- 0.879 (0.78)
O2-. 1.32 (0.21)
Why air bubbles don't disintegrate in water into different components due to difference in apparent weight (= ...
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2
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When calculating the distance between molecules in a solution, is it reasonable to approximate a sphere around each molecule? [closed]
I am attempting to calculate the average distance between molecules in a particular concentration of a solution. My first instinct was to treat the solution as a system of spheres surrounding the ...
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1
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Preparing aqueous solution of ethanol [closed]
You need to prepare $\pu{250.0 mL}$ of an aqueous solution of ethanol in the concentration will be $\pu{0.500 mol L-1}$. You have $\pu{100 mL}$ of a commercial solution of ethanol in water $(35.0\% \,...
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Density range of table salt?
Does anyone have a reference for the density range of common table salt $(\ce{NaCl})?$
A pure $\ce{NaCl}$ crystal has a density of $\pu{2.16 g/cm^3}.$ However, the salt granules in table salt don't ...
- 12.1k
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What are the least dense fluids?
This question left me wondering what other very light (condensed) fluids could exist, at any environmental condition.
Obvious candidates for the list are (at their Bp./1 bar)
LH2 (0.07 g/ml)
LHe (0....
- 12k
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What is the density of sodium trimethylsilylpropanesulfonate (DSS)?
I tried to look for the density of sodium trimethylsilylpropanesulfonate (DSS) online but could not find anything. Perhaps someone here measured it/knows where it may be found?
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Calculate molarity given density and mass percentage [closed]
Problem
Calculate molarity of a solution of $\ce{H2SO4}$ with density $\pu{1.198 g/cm3}$ and containing $27~\%$ mass of $\ce{H2SO4}.$
Answer
My approach
I converted the density to g/l. Then i took ...
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Is the density of a two-component mixture always between the densities of its individual components?
There exist eutectic mixtures, in which the freezing point of the mixture is below those of either component of the mixture, i.e., the freezing point of the mixture is not intermediate between that of ...
2
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1
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How do I figure out the composition of a material given specific densities?
The Problem
A waste material consists of sand (SG 2.7), a chemical salt (SG 2.1), and a dense plastic (SG 1.4). 200 g of a representative sample from the material is found to have a density of 2300 kg/...
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Moles of chlorine gas needed to make up an equivalent amount of saturated salt solution
I’m trying to solve a question about a saturated salt solution but am unsure of how to answer one of the parts or what it’s asking for.
The Problem
The maximum solubility of table salt (NaCl) in water ...
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3
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Volume calculation perchloric acid 70%
HClO4= 100.5, d HClO4=1.8, (ACO)2O=102, d (ACO)2O=1.1, H2O=18, d H2O=1
A) Preparation of 100 ml perchloric acid 0.1 Molar aqueous solution. below is my answer, but what I'm not sure is that the ...
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Why is platinum denser than gold?
The atomic masses of gold and platinum are 196.96657 u and 195.084 u respectively, meaning that (on average) an individual gold atom is heavier than an individual platinum atom.
At the same time, the ...
6
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2
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What makes some chemicals form steep density gradients in solution?
Caesium chloride and sucrose are both suitable for isopycnic centrifugation, and presumably not much else is. I'm unclear as to the mechanism by which they form useful density gradients. Wikipedia ...
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Largest change in the water level [closed]
Which would produce the largest change in the $\ce{H2O}$ level when added to water in a $\pu{25 mL}$ graduated cylinder?
(A) $\pu{10.0 g}$ of $\ce{Hg}$ $(d = \pu{13.6 g/mL})$
(B) $\pu{7.42 g}$ of $\ce{...
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0
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119
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Suspension liquid for ferrofluid that makes it float [closed]
I am currently devising a project to create a kinetic sculpture, similar to Sachiko Kodama. Does anyone know any suspension liquids that when applied, the ferrofluid floats on top?
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Density of water increases from 273 to 277 K due to increase in entropy?
In a set of questions that I was solving, the answer to one of the questions asking why the density of liquid water increases from 0 to 4 degrees C had the above answer: due to an increase in entropy. ...
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Theoretically predict the density of water
Is it possible to predict the density of water having just its molecular structure (basically obtain 1 g/cm3 at 3.96 °C)?
Are you aware of research/textbook that dive into this topic?
Is it able to ...