If your question is part of your high school or college/university homework, please use this tag. It signifies that instead of a direct answer, care should be taken to explaining the steps to the solution, preferably sticking to just giving helpful, conceptual hints. This tag may be applied to ...

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0answers
13 views

How to figure out which metals will be oxidized by aluminium ions? [on hold]

Which of these metals will be oxidized by the ions of aluminum? Why? How did you figure out that answer? A. magnesium B. zinc C. chromium D. iron E. nickel
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0answers
19 views

Could someone display the mechanism for the reaction of benzophenone with sodium borohydride?

I wondering about the details of the question like bonds broken/formed. As well, just general information on the reduction of ketones would be helpful.
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0answers
10 views

How to calculate the composure of a mixture by determined mass loss during heating? [on hold]

$$\ce{2NaHCO3 -> Na2CO3 +H2O +CO2}$$ A loss of $6.2~\mathrm{g}$ was seen when $25~\mathrm{g}$ of a mixture of sodium carbonate and sodium hydrocarbonate were heated to constant weight. ...
2
votes
2answers
48 views

How many grams of water would you add to 1.00 kg of 1.44m CH3OH(aq) to reduce the molality to 1.00 m CH3OH?

How many grams of water would you add to 1.00 kg of 1.44m $\ce{CH3OH (aq)}$ to reduce the molality to 1.00 m $\ce{CH3OH}$? I am absolutely stuck on the last question of my mastering chemistry ...
-1
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0answers
15 views

How to calculate the pH of this buffer solution? [on hold]

You prepare a buffer solution adding $\mathrm{61.06 g}$ of Benzoic Acid, $\ce{HC7H5O2}$ ($\mathrm{K_a = 6.4 x 10^{-5}}$ ), and 72.06 of Sodium benzoate, $\ce{NaC7H5O2}$ in $\mathrm{100 mL}$ of water. ...
0
votes
0answers
24 views

How to calculate the volume of this solution? [on hold]

Calculate the volume of the solution of Potassium hydroxide $\mathrm{0.1000 M}$ that is necesary to add to $\mathrm{15.00 mL}$ of a solution $\mathrm{0.2000 M}$ of Acetic acid to prepare a buffer ...
0
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1answer
23 views

Aqueous Chemistry: Ranking Ion Concentration

I am trying to rank the concentration of $\ce{PO4^3-}$, $\ce{NO3^-}$, and $\ce{Na+}$ that remain in a reaction. The reaction occurs when 100mL of 1.0M $\ce{Na3PO4}$ solution is mixed with 100mL of ...
0
votes
1answer
26 views

Identification of a hydrated salt [on hold]

3.22g of a hydrated salt $\ce{(M2SO4.10H2O)}$ was heated until no further loss in mass occurred; the residue mass was 1.42g. Calculate the atomic mass of M and hence identify it. How would I work ...
1
vote
3answers
40 views

Plotting p/T against T

This is about the ideal gas equation $$pV=nRT$$ to plot ${p}\over{T}$ against $T$, where ${nR}\over{V}$ is constant. How would this graph look like?
2
votes
2answers
94 views

Lowest CAS Registry Number on Record

I've been looking for a while and I still can't get a straight answer. I just need to know the lowest CAS Registry Number on record and the corresponding chemical.
0
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0answers
21 views

Wavelength of Sound Wave [closed]

What is the wavelength of the musical note A = 440 hz when it is propagated through air in which the velocity of sound is 343 m s–1? I am taking Chemistry online and I am unsure how to solve it. Thank ...
1
vote
2answers
64 views

How do I list these elements according to their radius?

$\mathrm{Z=33,\ Z=37,\ Z=9,\ Z=31}$ Since we shouldn't look at the periodic table, I found their groups and periods, what should I do next?
1
vote
1answer
47 views

Adding water on CH₃COONa. What's the new pH?

We have $10 \,\mathrm{L}$ of solution of $\ce{CH_3COONa}$ with concentration $C=1\,\mathrm{M}$ and $\mathrm{pH}=10$. Then we ad $90\,\mathrm{L} \space \ce{H_2O}$. The question is what will be the pH ...
2
votes
1answer
58 views

How to find the mass spectrum of Cl₃⁺?

The setting of this problem is on the moon of Jupiter: Io. Given that Chlorine exists in two isotopes: $\ce{{}^{35}_{17}Cl}~(33.3\%)$ and $\ce{{}^{37}_{17}Cl}~(66.7\%)$, what is the mass spectrum ...
0
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0answers
15 views

How do you find emf from water concentrations? [closed]

A concentration cell constructed from two hydrogen electrodes, both with $P(\ce{H2}) = 1.00$. One electrode is immersed in pure $\ce{H2O}$ and the other in $6.0~\mathrm{M}$ hydrochloric acid. What ...
0
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0answers
20 views

How to calculate the relative atomic mass of a metal via titration experiment? [closed]

$0.485~\mathrm{g}$ of a group 2 metal was dissolved in $25~\mathrm{cm^3}$ of $1~\mathrm{mol\cdot dm^{-3}}$ sulphuric acid. The solution that remained after the reaction needed $10~\mathrm{cm^3}$ of ...
0
votes
1answer
26 views

How to calculate the purity of a NaOH solution by titration? [closed]

'A solution was made by dissolving $\mathrm{7.5~ g}$ $\ce{NaOH}$, containing an inert impurity, in water and making up $\mathrm{250~ cm^3}$ of solution. If $\mathrm{20~cm^3}$ of this solution is ...
0
votes
2answers
21 views

Comparing Numbers with Different Significant Digit Precision

A while ago in chemistry class, I was asked to calculate the density of a rectangular prism, mass / (length * width * height), and then propogate the error. So I did the math and I got some value, ...
0
votes
1answer
35 views

A chemical compound with these conditions?

I am searching for a chemical compound wich meets these five conditions! slightly soluble in water layered strutcture ionic conductor thermochromism lead must be a part of it. I hope someone can ...
0
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0answers
22 views

Is glycerol/glycerin soluble in ethanol?

As titled, I wish to know if glycerol/glycerin is soluble in ethanol (not soluble, slightly soluble, very soluble)
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1answer
32 views

Limiting reactant and Percent Yield [closed]

When 8.8 grams of sodium chloride reacts with 4.5 grams of silver nitrate, how many grams of the precipitate silver chloride are produced? Would you end up with 21.43g AgCl and 3.77g AgCl when you ...
2
votes
1answer
57 views

Finding pH of a buffer solution

A $\ce{pH}$ 4.88 buffer was prepared by dissolving 0.10 mol of benzoic acid (Ka = 6.3 . 10-5) and 0.50 mol of sodium benzoate in sufficient pure water to form 1.00 L solution. To a 70.0ml aliquot of ...
0
votes
1answer
40 views

How to calculate the temperature from heat of neutralisation?

The heat of neutralization of $\ce{HCl~ (aq)}$ by $\ce{NaOH}$ is $\mathrm{-55.9~kJ/mol}$ $\ce{H2O}$ produced. If $\mathrm{50~ml}$ of $\mathrm{1.6~M}$ $\ce{NaOH}$ at 25.15 celsius is added to ...
0
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0answers
20 views

Iodine and persulfate kinetics: What can be deduced from graph?

From a graph of iodine concentration vs time of the reaction of iodide with persulfate, what can be deduced? Is it possible to find the order with respect to iodide and with respect to persulfate?
4
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1answer
34 views

How do I calculate the concentration of H₂SO₄ by a titration experiment with NaOH?

In my latest chem lab the objective was to create a primary standard of $\ce{NaOH}$ and use it to determine the concentration of sulfuric acid. The first part of the lab was determine the molarity of ...
4
votes
2answers
66 views

Finding rate constant at different temperature

For the reaction $$ \ce{2N2O5(g) -> 4NO2 + O2(g)} $$ the rate law is: $$ \frac{\mathrm{d}[\ce{O2}]}{\mathrm{d}t} = k[\ce{N2O5}] $$ At 300 K, the half-life is 2.50·104 seconds and the activation ...
0
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0answers
57 views

Histidine-Phosphate in Succinyl CoA synthetase and phosphoglycerate mutase enzyme

I would need to know the type of bond of histidine-phosphate in succinyl CoA synthetase enzyme. Can anyone help with this? Is it a Carboxy phosphate anhydride ? Is it the same type of bond of ...
3
votes
1answer
37 views

Transfer of energy

After completing a lab for my chemistry class I am finding it difficult to find the initial temperature of an iron nail after being heated. Procedure of the lab went as follows: heat an iron nail, ...
2
votes
2answers
78 views

Can Ketones next to a Nitrogen hetero atom tautomerise?

I worry that the electronegative N will stabilise keto form so much that equilibrium will be so far towards keto it would be unreasonable to call the enolisiation process a factor
3
votes
2answers
111 views

Experimental chemistry (Planning an experiment)

The benzyloxycarbonyl group (CBZ) is widely used to protect amines, especially in amino acid chemistry.A procedure to synthesise the CBZ derivative of glycine from glycine and benzyl chloroformate is ...
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0answers
35 views

Calculating mass and volume of two different substances required for one solution

I want to produce a solution, which contains $0.02~\mathrm{mol~L}^{-1}~\mathrm{Cu}^{2+}$ and $~0.2~\mathrm{mol~L}^{-1}~\mathrm{NH}_3$. The following substances are given: copper(II) sulfate ...
1
vote
1answer
67 views

Redox Question: Concentration of Pb2+ is unknown

What is the concentration of $\ce{Pb^{2+}}$ in a lake that has a pH of 6.0 and is in equilibrium with $\ce{PbO2(s)}$ and atmospheric oxygen? $\ce{PbO2(s) +4H+ +2e- -> Pb2+ +2H2O}$ log K = 49.2 ...
1
vote
3answers
61 views

Filling a buret tip before an experiment

I have a question that asks if the buret tip is not filled before the experiment what would happen (effect on molarity for acid/base titration). The way I'm thinking about it, it's not like you're ...
0
votes
1answer
45 views

How can I balance the redox reaction of sulfur dioxide with oxygen?

How do I balance this reaction using half-redox equations? $$\ce{2SO2 + O2->2SO3}$$ My work is: Oxidation: $\ce{SO2 + H2O -> SO3 + 2e- + 2H+}$ Reduction: $\ce{H2O + 2e- + O2 -> SO3 + ...
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votes
2answers
46 views

contact process<application of Sulphuric acid in industry>

Choose the two correct options from A-F, why it is not commercially suitable to dissolve $\ce{SO3}$ directly in water to give concentrated sulphuric acid instead of contact process? The major reaction ...
1
vote
1answer
62 views

Calculate the degree of dissociation of AlCl3

I'm having trouble figuring out where to go with this question. Calculate the degree of dissociation of $\ce{AlCl3}$ if molar conductivity of the solution is $31.3\ \mathrm{mS\ m^2\ mol^{-1}}$ and ...
0
votes
2answers
24 views

Chemical Equation & standard enthalpy change [closed]

Can a chemical equation be product --> reactants. For example in the equation, 2NCl --> N2 + Cl2, which is the product and which is the reactant? Also, how would you set up a standard enthalpy ...
1
vote
1answer
29 views

Denaturing of Proteins and Nucleic Acids - Effect of Temperature (Heating VS Cooling)

Heating a protein/nucleic acid will disrupt inter-molecular and intra-molecular forces in the tertiary structure. It will also interfere with the shape of the active site if the protein. Does this ...
2
votes
2answers
84 views

Why is an excited helium dimer created in this collision experiment?

Why does a collision between an excited helium molecule (He*) and a ground-state helium atom create He2*? Is it something to do with the lower-energy orbitals? I'm not really sure at all.
1
vote
1answer
80 views

Why is there an exponent 4 after the brackets in sp3?

My professor wrote an electron configuration for carbon as: 1s2 (sp3)4 I thought it was just 1s2 sp3 where did the 4 come from?
2
votes
0answers
27 views

Why would ethanol or water give poor yields in a peptide deprotection hydrogenolysis?

A homework question asks: The following reaction was carried out using ethanol or water as solvents, but gave poor yields in both cases. Suggest why this might be the case and how these problems ...
0
votes
1answer
45 views

How much sulfuric acid is necessary to completely react with lithium hydroxide? How do I find the concentration when a volume is given? [closed]

What is the molarity of sulfuric acid if 15.4 mL are required to react with 50.0mL of 0.353M lithium hydroxide? $$\ce{H2SO4 (aq) + 2LiOH (aq) -> Li2SO4(aq) + 2H2O(l)}$$
0
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0answers
3 views

required DM water quantity to dilute Acetic acid

I have acetic acid (glacial) 100% with a pH of 2.4. and i want to know how much DM water required to dilute acetic acid and obtain a pH of 4.3. as per observation 0.0001M is equal to 4.3 pH. so how ...
0
votes
3answers
58 views

Empirical Formula Worded Problem

5.00 g of nitrogen is completely converted into an oxide of nitrogen. The mass of the oxide formed is 19.3 g. The empirical formula of the oxide would be My working: $\ce{N2 + O_2 -> ...
0
votes
1answer
34 views

Galvanic cell using NaCl, Cu and Zn, why does it work?

Got a paper due tomorrow in chemistry, and my friends and I are totally stuck on this: Basically we mixed some regular salt (NaCl) into a glass of water and stuck a zinc nail and a copper nail into ...
0
votes
1answer
25 views

How do I calculate equilibrium partial pressures of $\ce{H2}$, $\ce{N2}$, and $\ce{H2O}$ and $K_{eq}$ for this problem?

This is the complete problem: A mixture of $0.10$ mol of $\ce{NO}$, $0.050$ mol of $\ce{H2}$, and $0.10$ mol of $\ce{H2O}$ is placed in a $1.0$ L vessel at $300$ K. The following equilibrium is ...
2
votes
0answers
26 views

How to predict the type of intrinsic defect?

How do we predict the type of intrinsic defects in materials. For example what are the intrinsic defects in $\ce{HgSe}$ and $\ce{Ba3N2}$ ?
2
votes
1answer
24 views

Factors to consider to predict EPR

What are the factors to consider when predicting the EPR spectrum of $\ce{Cu(Ox)P(CH3)3}$ where $\ce{OX}$ is the oxalate ion? I understand that there are several factors to consider for EPR (Electron ...
1
vote
1answer
21 views

Gas laws question, condensed partial pressure?

So I'm relatively new to gas laws as I just started learning it at school. I've been doing fine so far until I got stuck on this question, any ideas? A mixture of three gases N2, CO2 and O2 has a ...
2
votes
2answers
42 views

How to determine the composition for a sucrose/ zinc nitrate solution from its freezing point?

A $4~\mathrm{g}$ mixture of sucrose ($\ce{C12H22O11}$) and zinc nitrate ($\ce{Zn(NO3)2}$) is dissolved in $150~\mathrm{g}$ of water. If the resulting solution freezes at $-0.768~^\circ\mathrm{C}$, ...