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1. Half Reaction Method

Hello there, Although there are oxygens on both sides of the equation, there are two on the left and three on the right. Therefore, you need to add one water molecule on the left for compensation. HNO2 + H2O -> NO3- Since you have three hydrogen atoms on the reactants' side, add three to the...
2. Rates, whats wrong with my working?

You're welcome. Unfortunately, I still have not found a different answer. Is this textbook a recognised, leading one in chemistry? If not, then the answer key may be erroneous.
3. Chemistry The electrical work needed to produce a mole of lead in a chemical reaction

Hello there, Unfortunately, I'm not an expert in the area of thermal physics. I have always interpreted Gibbs Free Energy as the amount of energy available to do work in a system. Does that help?
4. Rates, whats wrong with my working?

Hello there, I get the same answer in mol/(L x s) as you. Could you verify that the correct answer is given in the same units? Thanks.
5. Chemistry The electrical work needed to produce a mole of lead in a chemical reaction

Hello there, I am unsure about how your solution addressed this question, but this is what I would do. 1) You need to understand this equation: ∆G = nFE0cell. 2) You can calculate ∆G for the entire reaction using tabulated values of ∆G for each reactant. That is, ∆G for the reaction = ∆G...
6. Thermochemistry and Equilibrium of Reaction

Hello there, You are missing a key equation: mc∆T = -mc∆T, where ∆T = Tf - Ti. I encourage you to learn this equation and then retry the problem. If you need any more help, please write back!
7. Simple electrochem prob

Hello there, This can be considered as a "tricky" question. I did not arrive at the right answer on my first try. You have to read the question carefully. Although you calculated the standard OXIDATION potential for Pd -> Pd2+ + 2e- correctly, you are asked for this half-reaction's standard...
8. Calculate Molar Enthalpy Change for Magnesium & Copper Sulphate Reaction

Hello there, I will start by writing the chemical equation: Mg + Cu(SO4)2 -> Cu + Mg(SO4)2 b) For this part, you know that Mg is in excess. Therefore, you simply need to find the amount of Cu(SO4)2 in mols. When you have this, then you know that the excess amount of Mg will be anything > the...
9. Solubility Problem - Involves Addition of Another Ion

Homework Statement How many moles of solid sodium fluoride should be added to 1.0 L of a saturated solution of barium fluoride, BaF2, at 25OC to raise the fluoride concentration to 3.0 x 10-2 mol/L? The solubility product constant for BaF2 is Ksp = 1.7 x 10-6 at 25OC. The Attempt at a...
10. Laboratory Chemisry Question - Redox Reaction

Homework Statement 1. Explain why the following chemical reaction would not be effective to determine [Fe2+] in a given solution. Fe2+ (aq) + H2O2 (aq)-> Fe3+ (aq)+ H2O(l) | in acidic solution Homework Equations The Attempt at a Solution Hello: I am thinking that there may be a lack of...
11. Is hydrogen non-metallic?

Hello: Hydrogen is not a metal; it is a gas at room temperature. However, it has an unique chemical property. Like the alkali metals, it can lose its electron and just be a H+ proton (since it has no more electrons); or it can act like an halogen and gain an electron, to become H-. Hope...

13. Applying Oxidation Numbers to Al + KClO4

Hello: I am having some trouble relating to the following question to the concept of oxidation numbers as required by my practice problem, and would appreciate any help. Thank you! --- 1. Explain why it is dangerous to grind a mixture of Al with KClO4 in a mortar and pestle. ---...
14. Rates of Reaction Problem - Verification

Hello everyone: For the following problem, I arrived at the correct answer but am unsure about the method used. Could someone please check my work to see if it is legitimate or if it is a fluke? Thank you. --- 1. The age of wine can be determined by measuring the trace amount of radioactive...
15. Arrhenius Equation - Chemical Kinetics

Thank you very much for your help!
16. Arrhenius Equation - Chemical Kinetics

Thanks for your reply, Mike H. I apologise; I didn't realize that this was the correct forum. If someone could please move this to the Homework Help section, that would be appreciated. I have rewritten my work with units: k = 4.3E13 \frac{1}{s} \times e^{\cfrac{-103 \frac{kJ}{mol}}{8314...
17. Arrhenius Equation - Chemical Kinetics

Hello everyone, I am having trouble with determining where I erred in the following exercise. If someone could point out my mistake, I would appreciate the help. Thank you! --- 1. The decomposition of N2O5 has an activation energy of 103 kJ/mol and a frequency factor of 4.3E13 s^-1 . What...
18. Possible Error in Chloric Acid's Lewis Structure

Thanks for your reply, ygggdrasil. Does this exception occur often? If so, what would be the maximum number of valence electrons allowed for chlorine? 20?
19. Possible Error in Chloric Acid's Lewis Structure

Hello everyone: I was looking at Wikipedia's page on chloric acid (http://en.wikipedia.org/wiki/Chloric_acid) and was wondering if the Lewis diagram there is correct. I will not link directly to it as it has a high resolution. It shows Cl with a lone pair of electrons having double bonds with...