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.

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56 views

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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1answer
36 views

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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4answers
140 views

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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0answers
50 views

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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0answers
41 views

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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2answers
90 views

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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57 views

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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14 views

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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2answers
358 views

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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1answer
48 views

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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2answers
416 views

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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2answers
2k views

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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1answer
56 views

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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1answer
33 views

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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2answers
564 views

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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1answer
403 views

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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2answers
2k views

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 ...
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0answers
206 views

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....
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1answer
64 views

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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1answer
7k views

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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1answer
800 views

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 ...
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1answer
64 views

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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1answer
44 views

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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3answers
1k views

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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1answer
616 views

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 ...
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2answers
342 views

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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2answers
39 views

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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0answers
54 views

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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1answer
126 views

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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57 views

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 ...
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0answers
44 views

What gas would be suited best to form a density gradient in a long tube? [closed]

I want to set up an aero-optics experiment using a sealed ~5 m length of pipe with a gas inside. The gas must form a density gradient, and must be transparent enough to view a target at the other end ...
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1answer
138 views

Separation of methanol–water mix in a plate distillation column

I conducted an experiment to separate methanol and water. I am trying to determine the mole fraction of the distillate collected but having a little trouble with the calculation. The flow rate was $\...
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0answers
46 views

Why are the OV and VO blocks of the CIS 1RDM zero?

I know the reduced density matrix has the form: $$ \gamma(\alpha,\beta) = \langle\Psi_N|c^{\dagger}_{\alpha} c_{\beta}|\Psi_n \rangle $$ but when $\Psi_N$ is the configuration interaction singles (CIS)...
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0answers
198 views

Predicting atomic weight and density of calcium [closed]

I have a question from school: Assuming that the element Ca had not been discovered, predict using the properties of the known element surrounding Ca its own properties such as its atomic weight ...
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2answers
306 views

Density and concentration of hydroiodic acid [closed]

I weighted my hydroiodic acid sample: 25 ml weight 34.1 g, so the density is about 1.364 g/ml. I want to know its concentration based on density. Does anyone have the corresponding density chart?
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1answer
202 views

Most dense hydrogen containing composition [closed]

I am searching for a composition which could host the most hydrogen atoms in a specific volume. Note that this density is sought for justifiable conditions in terms of pressure, temperature, ... and ...
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0answers
220 views

Over time what happens to soluble liquids with different densities

I have a case with two liquids: Water and another chemical which is miscible in water. The chemical has a density of 800 g/l so it's 20% less dense than water. Initially the chemical was mixed with ...
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0answers
29 views

Two common fluids that don't mix inside a labyrinth [closed]

I'm not sure in which SE site put this question. Imagine a typical child toy, where a bunch of spheres move by gravity through a labyrinth. Now imagine a sealed small labyrinth with two fluids. I'd ...
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1answer
501 views

What Value of Purity Do We Substitute in the Formula C=10PD/M

In the the formula $$C = 10P\frac{D}{M}$$ $C$ is the concentration of a substance in a solution, $P$ is the percent concentration (purity) of the substance, $D$ is the relative density of the ...
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1answer
35 views

Sample: How to calculate mass of nanopaticles with given density and Vol % [closed]

I'm trying to calculate the wt% and the mass of the nanoparticles in a ferrofluid solution. Attached is data from the supplier: ...
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2answers
454 views

How to reduce surface tension of oil?

I would like to create tiny colored drops slowly falling down in a transparent liquid. The diameter of the droplets must be around 2mm, and their speed must be approximately 0.5 mm / sec. For that, ...
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2answers
6k views

What is the least dense liquid under normal conditions?

What is the least dense liquid under normal conditions, room temperature, one atmosphere of pressure, doesn't combust upon contact with air, also wouldn't kill a human just for being in the same room ...
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28 views

Calculating Air Density and Effect of Air Composition

I have to calculate density of atmosphere, assuming that it is: 79% : N2 21% : O2 Does the percentage of gases affect the answer, and how can we find the density with such little information?
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1answer
312 views

Does iron nail sink in rubbing alcohol [closed]

I have been trying for so long to get answer
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1answer
344 views

When finding the liquid density which gives the most accurate results, a 25 ml Pycnometer or a graduated 10 ml cylinder?

Its 10 ml graduated cylinder with 25 ml of pycnometer, and we are measuring the density of the liquid(pure liquid) in each of the materials and we are suppose to compare the densities found , in terms ...
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1answer
482 views

How to make oil more heavy?

I would like to increase the density of a given oil (or anything that repels water) so that it is slightly heavier than water; to be able to precisely control how slow the oil would fall in the water. ...
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204 views

Determine Which has the higher density the pure liquids or solutions?

What i know that it immensely depends on their individual density, but am not really sure since doing research they was no solid answer. i just want a conformation if what am suggesting is correct.
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4answers
2k views

What is the smallest molar volume?

I wondered how small a volume a mole of material could occupy, so I started with carbon, which would need 12 grams. That's 60 carats, and there happens to be a famous 60 carat diamond. If my density/...
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2answers
117 views

Finding percentage of the gas in a binary gaseous mixture of the given density

At STP, the density of a gas in a vessel is $0.9002$. If the gas is a mixture of argon and helium, what percentage of the gas is argon? I am stuck on this. From what I can gather, the only ...