Search found 52 matches

by 605324529
Mon Mar 16, 2020 8:33 pm
Forum: Balancing Redox Reactions
Topic: 6M.1B
Replies: 1
Views: 90

6M.1B

Which is the stronger oxidizing agent for species in aqueous solution, Cu+2 or Ag+, under standard conditions? (a) Evaluate the standard potential of the appropriate cell; (b) write the net ionic equation for the corresponding cell reaction; (c) state your answer to the question.
Thanks!
by 605324529
Mon Mar 16, 2020 7:48 pm
Forum: Ionic & Covalent Bonds
Topic: Physical properties
Replies: 4
Views: 307

Physical properties

Based on how the periodic table is organized, can you identify some of the physical properties that are associated with the ionic and covalent character?
by 605324529
Mon Mar 16, 2020 7:45 pm
Forum: General Science Questions
Topic: Solubility comparison
Replies: 1
Views: 260

Solubility comparison

Why is calcium hydrogen carbonate (bicarbonate) more soluble than calcium carbonate?
by 605324529
Mon Mar 16, 2020 7:43 pm
Forum: General Science Questions
Topic: Borosilicate glass expansion
Replies: 1
Views: 145

Borosilicate glass expansion

Why does borosilicate glass expand less than other glasses when it is heated?
by 605324529
Mon Mar 16, 2020 7:41 pm
Forum: General Science Questions
Topic: Oxides of carbon and silicon
Replies: 1
Views: 123

Oxides of carbon and silicon

What accounts for the difference in properties of carbon and silicon oxides?
by 605324529
Mon Mar 16, 2020 7:38 pm
Forum: General Science Questions
Topic: Alien life
Replies: 1
Views: 140

Alien life

Is the existence of alien life forms based on silicon plausible?
by 605324529
Mon Mar 16, 2020 7:35 pm
Forum: *Haloalkanes
Topic: Friction
Replies: 1
Views: 119

Friction

I am not sure if this belongs to this section but, what is the molecular origin of friction?
by 605324529
Mon Mar 16, 2020 7:30 pm
Forum: *Alkanes
Topic: Alkaline environment
Replies: 3
Views: 292

Alkaline environment

I read recently that no virus can survive in al alkaline environment. Is this true?
by 605324529
Mon Mar 16, 2020 7:22 pm
Forum: General Rate Laws
Topic: unique average reaction rate change
Replies: 1
Views: 68

unique average reaction rate change

By what factor does the unique average reaction rate change if the coefficients in a chemical equation are doubled?
by 605324529
Mon Mar 16, 2020 7:19 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Ph of weak acid-weak base titration.
Replies: 1
Views: 274

Ph of weak acid-weak base titration.

Ant venom contains formic acid (HCOOH; “formica” is the Latin word for ant). Suppose you are at a pharmaceutical company working on a quick antidote and need to estimate the pH at the stoichiometric point when titrating a solution of formic acid. Estimate the pH at the stoi- chiometric point of the ...
by 605324529
Mon Mar 16, 2020 7:18 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: strong acid-strong base titration
Replies: 1
Views: 80

strong acid-strong base titration

The analyte consists of 25.00 mL of 0.250 m NaOH(aq), and the titrant is 0.340 m HCl(aq). Calculate (a) the pH of the original analyte solution and (b) the pH after the addition of 5.00 mL of the acid titrant.
by 605324529
Thu Mar 12, 2020 12:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.29
Replies: 3
Views: 114

5I.29

At 25 8C, K = 3.2 * 10^-34 for the reaction 2HCl(g) <--> H2(g) 1 Cl2(g). If a reaction vessel of volume 1.0 L is filled with HCl at 0.22 bar, what are the equilibrium partial pressures of HCl, H2, and Cl2?
I don't know how to approach this problem... Thanks in advance!
by 605324529
Mon Mar 02, 2020 1:52 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard energy H
Replies: 1
Views: 31

Standard energy H

Why is the standard energy of H2 --> 2H(+) + 2e equal to 0?
by 605324529
Mon Mar 02, 2020 1:50 pm
Forum: Balancing Redox Reactions
Topic: Electrochemical series.
Replies: 4
Views: 67

Electrochemical series.

What is meant by the electrochemical series?
by 605324529
Mon Mar 02, 2020 1:05 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation
Replies: 1
Views: 59

Nernst Equation

How do I know when to use log instead of ln in the Nernst Equation?
by 605324529
Sun Mar 01, 2020 11:33 pm
Forum: Balancing Redox Reactions
Topic: half rxn or ionization
Replies: 3
Views: 59

half rxn or ionization

How do you distinguish a conceptual half-reaction from an actual ionization?
by 605324529
Sun Mar 01, 2020 11:31 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Value of K
Replies: 2
Views: 62

Value of K

What is the value of K for a reaction that has Ecell = 0?
by 605324529
Sun Mar 01, 2020 11:30 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 1
Views: 35

Salt Bridge

Can any type of salt work to make the salt bridge or are there any specific types of salts that cannot be used?
by 605324529
Sun Mar 01, 2020 11:28 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: electrolytic cells
Replies: 1
Views: 52

electrolytic cells

What metal impurities cannot be removed from copper during refining by electrolysis?
by 605324529
Sun Mar 01, 2020 11:03 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 7th edition 6N.1
Replies: 4
Views: 232

Re: 7th edition 6N.1

First, n = 2.
Second, it's -0.45.
So you will have e^-35.02... which is equal to 6.1x10^-16
by 605324529
Sun Mar 01, 2020 9:08 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.5
Replies: 3
Views: 70

6M.5

Determine the standard cell potential:
2NO3(-)(aq) + 8H(+)(aq) + 6Hg(l) -->3Hg2(+2)(aq) + 2NO(g) + 4 H2O(l)

Thanks!
by 605324529
Sun Mar 01, 2020 3:08 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L. 1b
Replies: 1
Views: 48

6L. 1b

Calculate the standard reaction Gibbs free energy for the following cell reactions:

(b) 6 Fe(3+) (aq) + 2Cr(+3) (aq) + 7 H2O(l) --> 6 Fe(+2) (aq) + Cr2O7(-2) (aq) + 14H+ (aq), Ecell° 5 21.29 V

How do I find n for deltaGº= -nFE_cellº?

Thanks!
by 605324529
Sun Mar 01, 2020 11:42 am
Forum: Balancing Redox Reactions
Topic: 6K. 5D
Replies: 3
Views: 86

6K. 5D

Balance P4 → H2PO2- + PH3 in basic solution. I know that the half reactions are: 3 x (P4 + 8OH- → 4H2PO2- + 4e-) 12H2O + P4 + 12e- → 4PH3 + 12OH- and the answer is 3OH- + P4 → 3H2PO2- + PH3. But I don't know how the two half equations lead to that answer. Can somebody do it step by step, please?
by 605324529
Sun Mar 01, 2020 10:38 am
Forum: Balancing Redox Reactions
Topic: HW 6K.3b
Replies: 1
Views: 44

HW 6K.3b

Balance using oxidation and reduction half-reactions (takes place in an acidic solution). Please step by step! Thank you so much
. MnO42(aq) 1 H2SO3(aq) --> Mn21 (aq) 1 HSO42(aq)
by 605324529
Wed Feb 12, 2020 2:27 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: q of ice and q of water
Replies: 8
Views: 164

q of ice and q of water

Why does q_ice= -q_water?
Thanks!
by 605324529
Mon Feb 10, 2020 11:33 am
Forum: Phase Changes & Related Calculations
Topic: Reversible or Irreversible
Replies: 5
Views: 52

Reversible or Irreversible

If the question does not specify which type of expansion it is, should we assume it is irreversible?
thanks
by 605324529
Mon Feb 10, 2020 11:22 am
Forum: Phase Changes & Related Calculations
Topic: Reversible and Irreversible
Replies: 3
Views: 41

Reversible and Irreversible

What is the difference between reversible and irreversible expansions?
by 605324529
Sun Feb 09, 2020 11:11 pm
Forum: Balancing Chemical Reactions
Topic: Mass conservation in chemical reactions [ENDORSED]
Replies: 3
Views: 394

Mass conservation in chemical reactions [ENDORSED]

Why is mass conserved during chemical reactions?
by 605324529
Sun Feb 09, 2020 11:09 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Negative entropies
Replies: 3
Views: 39

Negative entropies

Can we have negative entropies and if yes, what does this mean?
by 605324529
Sun Feb 09, 2020 11:06 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: specific heat v.s molar heat
Replies: 2
Views: 64

specific heat v.s molar heat

What exactly is the difference between specific heat capacity and molar heat capacity?
by 605324529
Sun Feb 09, 2020 11:05 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy change
Replies: 3
Views: 44

Enthalpy change

How does the enthalpy change when the reaction is reversed?
by 605324529
Sun Feb 09, 2020 11:02 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy of a close
Replies: 2
Views: 39

Entropy of a close

Why does the entropy of a close system can decrease only if the entropy of its surroundings increases by a greater amount?
by 605324529
Sun Feb 02, 2020 7:27 pm
Forum: Ionic & Covalent Bonds
Topic: Bond Forming
Replies: 8
Views: 204

Bond Forming

If bonds are forming and breaking all the time then why don't things fuse or bind together when they touch each other?
by 605324529
Sun Feb 02, 2020 7:18 pm
Forum: *Organic Reaction Mechanisms in General
Topic: K meaning
Replies: 6
Views: 123

K meaning

What does K mean in the Boltzmann equation?
by 605324529
Sun Feb 02, 2020 7:16 pm
Forum: General Science Questions
Topic: Cold and Hot liquids in Freezer
Replies: 2
Views: 202

Cold and Hot liquids in Freezer

Why does a glass of hot water freeze faster than a glass of cold water?
by 605324529
Sun Feb 02, 2020 7:12 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic bonds in solutions
Replies: 9
Views: 179

Ionic bonds in solutions

Are ionic bonds broken when salt dissolves in water? And if so, then is dissolving a chemical change?
by 605324529
Sun Feb 02, 2020 7:11 pm
Forum: Properties of Light
Topic: Photons
Replies: 3
Views: 215

Photons

Can photons be directly seen?
by 605324529
Mon Jan 20, 2020 6:54 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6D.5
Replies: 2
Views: 136

6D.5

Calculate the pH, pOH, and percentage protonation of sol- ute in each of the following aqueous solutions: (a) 0.057 m NH3(aq)
by 605324529
Mon Jan 20, 2020 9:28 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6A.3a
Replies: 1
Views: 34

6A.3a

Estimate the concentrations of (a) H3O1 and (b) OH2 at 25 8C in 6.0 3 1025 m HI(aq).
by 605324529
Sun Jan 19, 2020 3:01 pm
Forum: General Science Questions
Topic: glow sticks
Replies: 1
Views: 60

glow sticks

How do glow sticks glow?
by 605324529
Sun Jan 19, 2020 2:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Volume and pressure
Replies: 4
Views: 44

Volume and pressure

How will changing the volume affect the pressure of a system at equilibrium?
by 605324529
Sun Jan 19, 2020 2:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Change in Volume?
Replies: 3
Views: 39

Re: Change in Volume?

The concentration will change and momentarily the system will be back of equilibrium but after a while, the system will go back to the same K. K will not change as long as the temperature doesn't.
by 605324529
Sun Jan 19, 2020 2:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Change in Pressure?
Replies: 2
Views: 41

Re: Change in Pressure?

The system might go out of equilibrium if the pressure changes the volume ( c = m/v) which will cause a change in the concentration. Then, however, the reaction will respond accordingly to minimize the effect of the change in pressure, leading to the system back to the same K.
by 605324529
Sun Jan 19, 2020 2:47 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Change in K when reaction is endothermic?
Replies: 2
Views: 25

Re: Change in K when reaction is endothermic?

K changes since it is temperature-dependent. Cooling an endothermic reaction shifts equilibrium to left and K decreases. Heating it [censored] equilibrium to the right and K increases.
by 605324529
Sun Jan 19, 2020 2:40 pm
Forum: General Science Questions
Topic: Proton and Electron attraction
Replies: 5
Views: 67

Re: Proton and Electron attraction

My question actually was referring to why do positive and negative charges attract? Protons and electrons attract because positive (protons) and negative (electrons) attract. But why does this occur?
by 605324529
Sun Jan 12, 2020 9:24 pm
Forum: General Science Questions
Topic: electromagnetic gradient
Replies: 1
Views: 47

electromagnetic gradient

In and electromagnetic gradient, which force is stronger, the electric or the magnetic?
by 605324529
Sun Jan 12, 2020 9:21 pm
Forum: General Science Questions
Topic: Proton and Electron attraction
Replies: 5
Views: 67

Proton and Electron attraction

Why do protons and electron attract?
by 605324529
Sun Jan 12, 2020 9:19 pm
Forum: Ideal Gases
Topic: Ideal gas law exceptions
Replies: 3
Views: 39

Ideal gas law exceptions

Does the ideal gas law works the same for noble gases as it does for the rest?
by 605324529
Sun Jan 12, 2020 9:14 pm
Forum: Properties of Electrons
Topic: Experiments of electrons
Replies: 5
Views: 179

Experiments of electrons

In which experiment does the electron behave like a wave? In which one does it behave like a particle?
by 605324529
Sun Jan 12, 2020 9:12 pm
Forum: Properties of Electrons
Topic: wave particle duality of electron
Replies: 2
Views: 133

wave particle duality of electron

Why are electrons considered both particles and waves?

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