Questions tagged [homework]
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173
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Calculating molar conductance of CaCl2
Ok, so the following question is given in my text book.
Of the molar conductance value of $\ce{Ca^2+}$ and $\ce{Cl^-}$ at infinite dilution are respectively $118.88\times10^{-4}$ and $77.33\...
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1
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How to calculate m/e value for the base peak in mass spectroscopy?
My working out:
Propan-1-ol : CH3CH2CH2OH
This can be broken up into:
CH3 + CH2CH2OH
CH3CH2 + CH2OH
CH3CH2CH2 + OH
Base peak = most abundant fragment formed (highest peak)
How do i know which ...
- 755
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1
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UV-Visible Spectroscopy in the analysis of sodium chloride in potato chips
Here is the question and answer out of an exam paper:
Firstly, I thought UV-Visible can also use radiation in the visible spectrum. Also when analyzing sodium chloride (a molecule), then UV-Visible ...
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2
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1H-NMR and deducing structures
here is the data booklet we must refer too:
Here is the exam paper solution:
I dont understand how they conclude this.
Peak areas and the chemical shifts seem to be different for me. For example ...
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1
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Which salt precipitates from a solution of ammonium oxalate and silver nitrate?
I am supposed to write the precipitation reaction for
$\ce{(NH4)2C2O4 + AgNO3 ->[\ce{H2O}]}$
Is my equation correct? I left out the Spector ions.
$$\ce{4(NH4) + 2 C2 +O4\rightarrow 4(NH4)2CO3}$$
- 2,652
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2
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648
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Best solvent for crystallization + mass recovered from crystallization + purity of the product
I have a chemistry final tomorrow and this question on my sample exam through me for a loop. I'm not entirely confident I can work out problems B and C, but those questions rely on the answer to A.
...
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1
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973
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How do I calculate the temperature of hot air in kelvin?
The question simply says “calculate the temperature of hot air in kelvin” on a data calculation section for this lab. We recorded:
volume change on cooling = 170 mL
original volume of hot air = 20 mL
...
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1
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275
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Chemical Potential of Idea gas?
Let's say we have a mixture of different ideal gases. I found that the chemical potential of a single component of the mixture is
$$\mu_{i}=g_{i}^{0}+Ln(\frac{f_{i}}{P_{ref}})$$
where $f_{i}$ is the ...
- 209
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1
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How do I calculate the enthalpy change when a gas is being used to heat water?
The question I'm trying to answer is:
Calculate the mass of butane gas that would be needed to heat $724\ \mathrm{cm^3}$ of water from an initial temperature of $7.44\ \mathrm{^\circ C}$ to $50.7\ \...
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Relation between number of equivalents of reactants
Consider the reaction $\ce{Sb2S3 + F2 -> SbF5 + SF6}$. If the milliequivalents of antimony, sulfur and fluorine are x, y and z respectively, then prove that $x+y=z$.
This is what I know: Number of ...
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4
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Gas Law problems with stoichiometry
Consider the following reaction : $\ce{H2 + Cl2 -> 2HCl}$
A) If you have 15.00 liters of hydrogen reacting with 10.00 liters of chlorine at STP, how many liters of HCl would you produce?
B) What ...
- 147
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1
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How to calculate molality, molarity and mole fraction given density (g/mole)?
Calculate the molality, molarity and mole fraction of a $\ce{CuSO4}$
in a 17% m/m aqueous solution (density of the solution is 1.367 g/mole)
I did .17 * 1.367 to find grams of $\ce{CuSO4}$
and .83 * ...
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1
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3k
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How to estimate pH?
How you you calculate/estimate the pH of a solution with 3 components all of different pHs?
Is there a paper describing this?
For example:
0.1M Buffer PCTP at pH 9.5
1.6M Sodium Dihydrogen Phosphate ...
- 385
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1
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How do I write the complete and net ionic equations for Insoluble compounds?
So, I was doing my homework and had to write out the complete equation and net ionic equation for a combination of Lead (II) Iodate and Sodium Hydroxide.
So my equation is given as:
$\ce{Pb(IO3)2_{(...
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2
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How will citric acid be deprotonated by pyridine?
Why do we deprotonate that specific hydrogen as opposed to any other one? What information does the table on the right give us? It seems unrelated to citric acid - where does the fluorine come from?
- 135
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2
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Predicting electronic geometry, observable geometry, and hybridization for any atom in a molecule
Can someone please explain the intuition around the answers to this problem:
I'm finding it very confusing because it seems like you have to nitpick between two resonance structures to get the ...
- 135
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1
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867
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Law of Definite Proportion: Do the numbers indicating moles count?
I need to find the ratio of a substance as it converts from a bicarbonate to a carbonate:
ex:
$\ce{Fe(HCO3)2 -> FeCO3 + CO2 + H2O}$
$\ce{Fe(HCO3)2} / \ce{FeCO3}$ = $3/2$ *using molar masses
But ...
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-1
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2
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353
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How does pressure shift equlibrium
Here is a question from my practice problems:
I know that the answer is A, but I don't know why. Is it because A has the most moles of gas on the left? thanks
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2
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2k
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What is the multiplicity of this signal in the ¹H NMR of glutamine in D₂O
The 2 Hydrogens near the carbonyl (the lower 2 $\ce{H}$s are not bonded to the nitrogen) should be the most deshielded so I think they appear as the rightmost peak in the NMR. Are these 2 $\ce{H}$s a ...
- 585
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1
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380
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Is 2,3-dimethylprop-1-ene a possible organic structure?
Is 2,3-dimethylprop-1-ene a possible organic structure?
I am not sure how to approach this, what would the correct name of this molecule be?
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2
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List in order of increasing radius
List in order of increasing radius:
a) Rb, K, C5, Kr
For this one I got C, Kr, K, Rb
b) Ar, Cs, Si, Al
This I got: Ar, Si, Al, Cs
Does anyone know if this is correct? I don't have the solution ...
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Specific heat capacity and the periodic table
Can someone explain me how can I use the periodic table in order to find the specific heat capacities of some elements? (for example, of Aluminium )
The question I have encountered is as follows:
...
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1
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577
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Product/(s) of the following reaction
I was wondering what the product will be in the following reaction:
$$\ce{H3COOCH3 ->[\ce{H+}]} \:?$$
I was thinking about $\ce{CH3COOH}$ being a product but I do not know the mechanism.
user570