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5 views

What is the volume of one mole liquid ammonia at -50 °C?

If I start with $1~\mathrm{mol}$ of $\ce{NH3}$ gas and condense it into a liquid at around $-50~^\circ\mathrm{C}$ about how many liters of $\ce{NH3}$ will I have? How do I calculate this.
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1answer
8 views

How is 12M of sulfuric acid in 1 L bottle 72% w/w?

According to this, $12~\mathrm{M}$ of $\ce{H2SO4}$ is $72~\mathrm{w/w\%}$. When I try to convert $12~\mathrm{M}$ of $\ce{H2SO4}$ to $\mathrm{w/w\%}$ I get $117\%$ which is obviously wrong. $$\small ...
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0answers
6 views

Kinetics and Half Lives Using Pressure

For a certain first-order gas-hase reaction A $\rightarrow$ B + C the time required for half of an initial amount of A to decompose is 8.8 min. If the initial pressure of A is 400 mmHg, the time ...
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1answer
12 views

Hydrolysis of Radiolabeled Esters

Hydrolysis of C$_6$H$_5$COO$^{18}$CH$_3$ with aqueous NaOH produces what final product. (a) CH$_3$$^{18}$OH (b) CH$_3$CO$^{18}$ONa (c) CH$_3$C$^{18}$OONa (d) CH$_3$$^{18}$ONa (e) CH$_3$OH The ...
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1answer
12 views

Calculating Enthalpy Changes at Different Temperatures

To calculate $\Delta$H, the change in ethalpy at $100$˚C for the reaction below, one needs what addition information? N$_2$ $(g)$ + 3 H$_2$ $(g)$ = 2 NH$_3$ $(g)$ $\Delta$H˚ = $-92.0$ kilojoules ...
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0answers
6 views

Distribution of acid in Organic and Aqueous Phases

The value for the distribution constant for an organic acid, HA, between chloroform and water is $10^2$. The dissociation constant of the acid in water is $10^{-5}$, and it can be assumed that it ...
4
votes
1answer
35 views

Can a tertiary enamine tautomerize to an imine?

Which of the following compounds does not show tautomerism? The correct answer is (a), and I'm curious if this is because to show tautomerism, there can't be any net charge. For instance, ...
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0answers
17 views

Finding Chemical Unknowns

An unknown compound was found to react with sodium hydride with the evolution of hydrogen. The compound could not be acetylated under the normal conditions for acetylation. The compound resisted ...
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0answers
13 views

molecular formula of copper (II) sulphate hydrate [on hold]

the molar mass of CuSO4 is 160 g/mol and H2O is 18 g/mol. how to find the no of moles of CuSO4 and H2O?
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1answer
46 views

Any chemicals combines readily oxygen?

I am designing an industrial process which can remove oxygen from air. This chemical should combine readily with oxygen in the presence of heat. In particular, I am looking for a chemical with the ...
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0answers
12 views

Hydrogen visible transition [duplicate]

Why is there only four visible transitions in the hydrogen atom? What causes the hydrogen atom to only have the four visible transitions?
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0answers
24 views

Understanding a mass percent problem [on hold]

An ingenious AP Chemistry student is given a 50.0 gram sample of a homogeneous mixture of sodium chloride, sodium phosphate and sodium nitrate. The student is also given 2 unlabelled bottles by the ...
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1answer
40 views

Hydrogen visible transitions

When dealing with electrons and the electromagnetic spectrum, why are there only four visible transitions in the hydrogen atom?
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votes
1answer
97 views

Reactivity of propellanes

Why is [1.1.1]propellane considerably less reactive than either [2.2.1]propellane or [2.1.1]propellane as illustrated in the hydrogenation reactions pictured below?
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0answers
19 views

Precipitation of multiple ions in solution

I'm trying to figure out what exactly happens if you have 2 salts dissolved and then slowly evaporate the water: I have a solution containing 1 mol each of $\ce{Na+}$, $\ce{K+}$, $\ce{Cl-}$ and ...
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0answers
17 views

What is the equilibrium equation for this reaction? [on hold]

For a Chemistry assignment I was asked to find the equilibrium equation for the following: When Potassium Thiocyanate ($\ce{KSCN}$) is mixed with Iron (III) Nitrate ($\ce{Fe(NO3)3}$ in solution, ...
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1answer
31 views

Question on dilution from mixing multiple solutions

I have a homework problem as follows: A solution was prepared by mixing $25.0\ \mathrm{mL}$ of $0.208\ \mathrm{M}$ $\ce{Fe(NO3)3}$ and $4.50\ \mathrm{mL}$ of $0.00190\ \mathrm{M}$ $\ce{KSCN}$ and ...
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1answer
19 views

Is there a certain amount of titrant that is ideal?

For an AP chem lab dealing with determining the amount of citric acid in orange juice by titrating with NaOH, one of the discussion questions goes like this: Choose an amount of beverage to be ...
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1answer
30 views

Elements and compounds [on hold]

I humbly appreciate if you will answer these ff. questions. Can you tell whether a substance is an element or a compound based on its physical appearance? Knowing that an element cannot be broken ...
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0answers
9 views

pH of diluted mixture of HCl in differing initial concentrations [on hold]

Problem: 200 ml of 1 M $\ce{HCl}$ is mixed with 300 ml of 6 M $\ce{HCl}$ and the final solution is diluted to 100 ml. Calculate the molar concentration of $\ce{H+}$.
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votes
1answer
43 views

Find the mass of protons, neutrons, etc

Use the oxygen to describe how atom is built. There has to be the amount of charges, mass of isolate, mass of charge. My approach: Protons: 8 Mass of the material: 16 Neutrons: 8 Electrons: 8 ...
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0answers
31 views

Calculating the pH of a diluted aqueous solution [on hold]

A 50 ml solution with pH = 1 is mixed with a 50 ml solution of pH = 2. What is the pH of the mixture?
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0answers
29 views

Which of the following is the best desciption of cellulose [on hold]

a. a condensation polymer made from ethylene monomers b. a condensation polymer made from glucose monomers c. an addition polymer made from ethylene monomers d. an addition polymer made from ...
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0answers
11 views

The solubility of salt A in water 40 g/l at 25 °C [closed]

10 g of salt A are dissolved in water to form 500 ml solution x at 25 °C. Find the concentration of the resulting solution x
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0answers
25 views

Mass percentage of KClO3 in decomposition reaction

When heated, a 3.40 g sample mixture of $\ce{KClO3}$ decomposes and produces 685 cm$^3$ $\ce{O2}$ gas at 30 $^{\circ}\mathrm{C}$ and 101 kPa. What is the mass percentage of $\ce{KClO3}$ in the ...
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2answers
44 views

Why is this named incorrectly?

In my Ap chem class I got this sheet with the names of a bunch of common polyatomic ions. One of them is named monohydrogen phosphate ($\ce{HPO4^2-}$). In naming, I learned not to use ‘mono-’ if it’s ...
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4answers
132 views

Work Done Upon Molecules

In which of the following processes is energy transferred into the substance by work ($w > 0$)? a) Expansion of a gas against the surroundings b) Expansion of a gas into a vacuum c) Vaporization ...
1
vote
1answer
44 views

Ideal among the given gases

Which one among the following shows maximum ideal behaviour? $\ce{NH3}$ $\ce{HCl}$ $\ce{Rn}$ $\ce{H2O}$ Ammonia and water have hydrogen bonding so they're ruled out. That leaves ...
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0answers
10 views

How does Glucose synthesis via the Kiliani-Fischer reaction work? [closed]

Synthetise glucose from D-1,3 dihydroxy aldehyde propanal.
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votes
1answer
39 views

In which of the compounds ONO bond angle is maximum?

Which has maximum $\ce{ONO}$ angle.? $\ce{NO3-}$ $\ce{NO2+}$ $\ce{NO2-}$ $\ce{NO2}$ According to me $\ce{NO2+}$ should have max angle because the structure is linear but in answer it is given ...
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vote
2answers
33 views

Which one should be placed on axial position lone pair or electronegative element?

In one question I found that it is given $\ce{XeF2}$ and $\ce{CO2}$ have the same shape? $\ce{CO2}$ is linear. But in $\ce{XeF2}$ if the fluorine is placed on axial position then only shape is linear. ...
2
votes
1answer
24 views

Diluting an NaCl solution with specific glassware

I have a 0.3 M NaCl stock solution and need to create a 0.01 M NaCl solution that is 50 mL. The only tools I am given are volumetric pipettes that are 10.0, 5.0, 1.0 and 0.5 mL and 50.0 mL volumetric ...
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0answers
30 views

Where does a proton attack in unsaturated cyclic ethers, epoxides and cyclic ethers in presence of another hydroxyl group? [on hold]

I am working out on some problems on alkenes and alkynes reactions like OMDM, HBO, epoxidation, deydration of alcohol and more but some problems came across me involving structures in which oxygen is ...
5
votes
1answer
42 views

Finding structure of C6H12O with several reactions

Full Question : An organic compound A (molecular formula $\ce{C6H12O}$) does not change the colour of acidic dichromate solution. Compound A on treatment with $\ce{H2SO4}$ produces alkene which on ...
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votes
1answer
32 views

How to calculate the mass of oxygen produced in the decomposition of potassium chlorate? [closed]

How many grams of $\ce{O2}$ are produced in the decomposition of $43.4~\mathrm{g}$ $\ce{KClO3}$? $$\ce{2KClO3(s) -> 2KCl(s) + 3O2(g)}$$
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vote
1answer
31 views

The pentagonal pyramidal structure of XeOF5- [closed]

Why does the $\ce{XeF6}$ molecule have an octahedral structure while $\ce{XeOF5-}$ has a pentagonal pyramidal structure, despite both molecules having 7 electron pairs?
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votes
1answer
36 views

Equilibrium of liquid-vapour at boiling point; which is equal, kinetic or potential energy?

A liquid is in equilibrium with its vapor at boiling point. On average do the molecules in the two phases have equal potential energy or equal kinetic energy? Why? I can't really decide ...
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2answers
44 views

Oxidation of Carbons

In which of the reactions below is the first compound in the equation NOT oxidized? The correct choice is (D), which can be seen through process of elimination, but I was wondering how to do this ...
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0answers
21 views

Chemical Equillibria Comparisons

In which of the following reactions is the equilibrium farthest to the left? a) $\ce{P4O10 + $x$ H2O <=> 4 H3PO4(aq)}$ b) $\ce{AlCl3 + $x$ H2O <=> [Al(H2O)6]^3+ + 3 Cl- (aq)}$ c) ...
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votes
0answers
48 views

The density of Nitrogen at 0 degrees Celsius and 1 atmosphere is most nearly equal to which of the following quantities?

The density of nitrogen at 0 degrees Celsius and 1 atmosphere is most nearly equal to which of the following quantities? a) 0.001 g/L b) 0.01 g/L c) 0.1 g/L d) 1 g/L e>) 10 ...
0
votes
1answer
32 views

How to determine which substance is the strongest base / acid?

What is the simplest way to determine which substance, from a list, is the strongest base/acid? For instance, which is the strongest acid here? $\ce{HClO}$ $\ce{HClO2}$ $\ce{HClO3}$ ...
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vote
1answer
42 views

How to find the amount of moles given mass percentage data

A hydrated aluminium sulphate, $\ce{Al2(SO4)3.xH2O}$, contains 8.10% of aluminium by mass. Find the value of x. My attempt: (Assuming 100g sample) Calculate the amount of aluminium using the ...
-1
votes
1answer
14 views

Get K for a weak acid equilibrium when given the ionization percentage

There is some weak acid with a concentration of $0.0284$ M, which is ionized by $6.70$%. What is the value of $K_a$? So we got $$\ce{HA <=> H+ + A-}$$ The formula for the ionization ...
3
votes
1answer
19 views

Find the stoichiometric coefficient of a reactant given Kp, Kc, and the stoichiometric coefficient of the product

Have an hypothetical equilibrium reaction: $$\ce{2A(s) + $X$B(g) <=> 3C(g)}$$ With the constants $$K_p = 0.0105\\K_c=0.45$$ Both at $250\ \mathrm{^\circ C}$. What is the ...
3
votes
1answer
15 views

Calculating [HI] given Kc, [H2], and [I2] for the reaction 2HI <-> H2+I2

In the reaction in equilibrium $$\ce{2HI} \leftrightarrow \ce{H2 + I2}$$ The value $K_c$ is $0.0198$ at $721$ K. Calculate $\ce{[HI]}$ at $721$ K if $\ce{H2} = 0.0120$ M and $\ce{I2} = ...
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votes
1answer
31 views

Calculating pH: Weak Acid, Strong Base

This is a question that had me puzzled for quite a while. I feel that information is missing. A weak acid, $\ce{HA}$, $K_a = 1.0$ x $10^{-4}$, is titrated with $\ce{NaOH}$. At the equivalence ...
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0answers
24 views

How to calculate the concentration of a substance within a compound in a solution

A solution is made by dissolving $\mathrm{8.50~g}$ of $\ce{NaNO3}$ and $\mathrm{16.40~g}$ of $\ce{Ca(NO3)2}$ in enough water to give $\mathrm{2000~cm^3}$ of solution. What is the concentration of ...
0
votes
0answers
25 views

Determining which substance has the highest vapor pressure

I'm learning about intermolecular forces. This is part of the exercise: Which substance will have the highest vapor pressure? $\ce{CH4}$ $\ce{CH3CH2OH}$ $\ce{CHCl3}$ ...
3
votes
2answers
46 views

How to synthesise (E)-5-methylhex-3-en-2-one via a Wittig reaction?

I am trying to understand the Wittig reaction and am having difficulties in bringing all the information together to answer a question. I have been asked to synthesize compound A: The question asks ...
8
votes
1answer
107 views

What's the reaction type of the Hydrogen shift?

Rearrangement of cycloheptatrienyl carbene yields heptafulvene via a hydrogen shift. I see that the reaction is favorable because there is a conjugative effect with the $\pi$ system of the ring in ...