Search found 45 matches
- Fri Dec 07, 2018 12:15 am
- Forum: Amphoteric Compounds
- Topic: Acidic, Basic, and Amphoteric Oxides
- Replies: 2
- Views: 418
Re: Acidic, Basic, and Amphoteric Oxides
It would be basic if you have metal element in the formula; it would be acid if you have nonmetal element in the formula; it would be amphoteric if you have metalloid in the formula
- Fri Dec 07, 2018 12:14 am
- Forum: Amphoteric Compounds
- Topic: Amphoteric clarification
- Replies: 5
- Views: 562
Re: Amphoteric clarification
Yes. It depends on the reaction you have.
- Fri Dec 07, 2018 12:13 am
- Forum: Amphoteric Compounds
- Topic: 7th ed. 6A17
- Replies: 3
- Views: 366
Re: 7th ed. 6A17
because Bi is a metalloid.
- Fri Dec 07, 2018 12:13 am
- Forum: Amphoteric Compounds
- Topic: Definition
- Replies: 6
- Views: 622
Re: Definition
A substance which can act as either an acid or a base is described as being amphoteric.
- Fri Dec 07, 2018 12:12 am
- Forum: Amphoteric Compounds
- Topic: Determining Amphoteric Compounds
- Replies: 3
- Views: 291
Re: Determining Amphoteric Compounds
as long as you have a metalloid in the formula, the substance is a amphoteric compound.
- Fri Dec 07, 2018 12:11 am
- Forum: Amphoteric Compounds
- Topic: What makes As2O3 Amphoteric?
- Replies: 2
- Views: 513
Re: What makes As2O3 Amphoteric?
A substance which can act as either an acid or a base is described as being amphoteric. An amphiprotic substance is one which can both donate hydrogen ions (protons) and also accept them.
As2O3 is amphoteric because As is a metalloid
As2O3 is amphoteric because As is a metalloid
- Fri Dec 07, 2018 12:09 am
- Forum: Amphoteric Compounds
- Topic: BaO
- Replies: 5
- Views: 1807
Re: BaO
BaO is basic; any group1 metal's oxide are basic
- Sat Dec 01, 2018 1:25 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: H+ Acidic and OH- Basic
- Replies: 4
- Views: 627
Re: H+ Acidic and OH- Basic
I think that's only two ways of demonstrating. Acids and Bases: Lewis vs. Bronsted. There are two complementary definitions of acids and bases that are important: the Bronsted (or Bronsted-Lowry) definition: an acid is a proton (H+ ion) donor, and a base is a proton acceptor; the Lewis definition: a...
- Sat Dec 01, 2018 1:23 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Strength of an acid
- Replies: 14
- Views: 1703
Re: Strength of an acid
higher electronegativity difference means stronger acids (imagine H2S and HF)
- Sat Dec 01, 2018 1:21 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acid vs base [ENDORSED]
- Replies: 15
- Views: 1597
Re: Acid vs base [ENDORSED]
acids donate H+ and accepts e-; while bases donate e- and accepts H+
- Sun Nov 25, 2018 4:12 pm
- Forum: Hybridization
- Topic: sp orbitals
- Replies: 3
- Views: 345
Re: sp orbitals
the number of p orbitals
- Sun Nov 25, 2018 4:11 pm
- Forum: Hybridization
- Topic: double bonds
- Replies: 14
- Views: 1264
Re: double bonds
a double bond has one pi bond and one sigma bond. In a triple bond, there is one sigma bond and two pi bonds now due an additional side-to-side overlap.
- Sun Nov 25, 2018 4:07 pm
- Forum: Hybridization
- Topic: Hybridization and Hybrid Orbitals
- Replies: 4
- Views: 557
Re: Hybridization and Hybrid Orbitals
I think they are the same thing, just in different ways of telling
- Fri Nov 23, 2018 10:06 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent - Lone Pairs
- Replies: 8
- Views: 965
Re: Bent - Lone Pairs
Yes, shape for an AX2E and AX2E2 molecule are bent.
- Fri Nov 23, 2018 10:05 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs on the Central Atom
- Replies: 5
- Views: 541
Re: Lone Pairs on the Central Atom
because the substance wants its structure to be energy minimized; but the lone pairs and the electrons bonds will have repulsive forced which require more energy. in order to reduce energy, the bond electrons will go away from the lone pairs, affecting the shape.
- Fri Nov 23, 2018 10:02 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Difference Between Position and Shape
- Replies: 2
- Views: 313
Re: Difference Between Position and Shape
shape is determined two parts of electrons: bonds and lonely pairs.we only have to memorize the shape of the substance based on the vespl model
- Thu Nov 15, 2018 12:35 am
- Forum: Lewis Structures
- Topic: Octet rule question
- Replies: 6
- Views: 805
Re: Octet rule question
atoms before the period 3 must have a octet rule. Meanwhile, except the central atom, atoms aside should also obey the octet rule
- Thu Nov 15, 2018 12:34 am
- Forum: Lewis Structures
- Topic: VSEPR Model
- Replies: 6
- Views: 981
Re: VSEPR Model
from the previous learning, we actually did not really how the molecules look like or its shape; the resonance and the double or more bond we learn actually does not have any effect for the shape. so from the vsepr model, we should learn the practical model
- Thu Nov 15, 2018 12:31 am
- Forum: Lewis Structures
- Topic: Formal Charge
- Replies: 14
- Views: 1328
Re: Formal Charge
I think it is better to have zero formal charge on the central atom; though the electronegativity is also very important, the formal charge of the central atom is more important
- Mon Nov 05, 2018 9:51 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Why does PCl5 break the Octet Rule?
- Replies: 8
- Views: 7156
Re: Why does PCl5 break the Octet Rule?
because it is on the period 3, so it order to have the lowest energy structure, the pcl5 can break the octet rule.
- Mon Nov 05, 2018 9:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Do we need to memorize formulas and constants?
- Replies: 2
- Views: 692
Re: Do we need to memorize formulas and constants?
no. I think all the equations and constant are covered in the test paper. The only thing we need to know is to make sure that we know how to use those equations.
- Mon Nov 05, 2018 9:48 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Type of calculator
- Replies: 8
- Views: 1124
Re: Type of calculator
that one is absolutely fine.
- Mon Nov 05, 2018 9:47 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Memorizing equations [ENDORSED]
- Replies: 5
- Views: 908
Re: Memorizing equations [ENDORSED]
I think all the equations will be posted on the test material. The only thing we need to do is to make sure we know how to use them
- Mon Nov 05, 2018 9:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Question from textbook
- Replies: 2
- Views: 339
Re: Question from textbook
Use 2.111g Na2CO3 and the 250.0mL to get the molarity. 0.08mol/L.
Take the 2.15mmol Na+ ion and convert into moles. There are two Na+ ion per Na2CO3 molecule. Using the molarity, we can convert that into how many liters of the solution we need.
you can find the answers for part c by the same way
Take the 2.15mmol Na+ ion and convert into moles. There are two Na+ ion per Na2CO3 molecule. Using the molarity, we can convert that into how many liters of the solution we need.
you can find the answers for part c by the same way
- Mon Oct 29, 2018 3:12 pm
- Forum: Lewis Structures
- Topic: lewis structure
- Replies: 10
- Views: 1084
Re: lewis structure
you mean the central atom ? choose atom with lowest ionization energy as central atom
- Mon Oct 29, 2018 3:11 pm
- Forum: Lewis Structures
- Topic: central atom
- Replies: 7
- Views: 613
Re: central atom
choose the atom with the lowest ionization energy as the central atom
- Mon Oct 29, 2018 3:09 pm
- Forum: Lewis Structures
- Topic: 2 lone pairs
- Replies: 5
- Views: 598
Re: 2 lone pairs
it does not matter whether you put it on the top or at the bottom. The only thing you only need to pay attention to is to put these two dots on different sides
- Mon Oct 29, 2018 3:07 pm
- Forum: Lewis Structures
- Topic: Lines that Represent Bonds
- Replies: 7
- Views: 642
Re: Lines that Represent Bonds
line means shared electrons, while the dots means lone pairs. These two are used in different situations and should be treated differently
- Mon Oct 29, 2018 3:06 pm
- Forum: Lewis Structures
- Topic: octets
- Replies: 13
- Views: 1134
Re: octets
when a atom has 8 valence electrons it is an octet
- Mon Oct 29, 2018 2:05 pm
- Forum: Lewis Structures
- Topic: Dots in Lewis Stucture
- Replies: 14
- Views: 1257
Re: Dots in Lewis Stucture
I think it does matter. You should put electron on each side first and then make the pairs.
- Mon Oct 29, 2018 2:04 pm
- Forum: Lewis Structures
- Topic: Lewis Structure for Compounds
- Replies: 6
- Views: 460
Re: Lewis Structure for Compounds
Because you two positive particles will repel to each other.
- Mon Oct 29, 2018 2:02 pm
- Forum: Lewis Structures
- Topic: Delocalized Electrons
- Replies: 5
- Views: 475
Re: Delocalized Electrons
delocalized electrons are electrons in a molecule, ion or solid metal that are not associated with a single atom or a covalent bond. The term is general and can have slightly different meanings in different fields. It's just a general term and I don't think it will be tested
- Sat Oct 20, 2018 8:56 pm
- Forum: Properties of Light
- Topic: De Broglie's equation [ENDORSED]
- Replies: 7
- Views: 1215
Re: De Broglie's equation [ENDORSED]
you can only use v=h/p for things with matter, for p=mv. if you wanna use that equation for massless photons, you willl be unable to put any numbers for m
- Sat Oct 20, 2018 8:48 pm
- Forum: Properties of Light
- Topic: Calculating the wavelength of light
- Replies: 7
- Views: 1223
Re: Calculating the wavelength of light
it is both correct to use c=3x10*8or 2.998x10*8; the only difference is that the latter is more precise. I think in the exams you can use c=3x10*8 directly.
- Sat Oct 20, 2018 8:46 pm
- Forum: Properties of Light
- Topic: Equations
- Replies: 7
- Views: 558
Re: Equations
1.hv=c
2.lamthum=h/p=h/mv
3.E-work function=1/2mv2
2.lamthum=h/p=h/mv
3.E-work function=1/2mv2
- Sat Oct 13, 2018 3:13 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity and Dilution
- Replies: 11
- Views: 4499
Re: Molarity and Dilution
molarity=m(kcal)/M(kcal)/V(KCL)
- Sat Oct 13, 2018 3:12 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Changing Units
- Replies: 10
- Views: 842
Re: Changing Units
I think you should use l instead of ml, for the l is the standard units
- Sat Oct 13, 2018 3:10 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity
- Replies: 4
- Views: 584
Re: Molarity
you shouldn't use m1v1=m2v1 this time. the equation you should use is that the mole of kmno4 is the same. so you should calculate the moles of kmno4 in the 20ml solution first.
- Sat Oct 13, 2018 3:07 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Units?
- Replies: 8
- Views: 813
Re: Units?
It depends on the question. But usually ,when we say molarity, it should be L for 1 molarity= 1mol/l
- Sun Oct 07, 2018 11:22 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Calculation error help!
- Replies: 2
- Views: 442
Re: Calculation error help!
you should use the formula n=m/M for the moles of kcl; and then you should use the formula molarity=n/v . the first 75ml here is just useless. you only need the final volume.
- Sun Oct 07, 2018 11:18 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity formula
- Replies: 6
- Views: 618
Re: Molarity formula
I think you can use if whenever you have all the numbers. mv=mv is available all the time without any contidions:)
- Sun Oct 07, 2018 11:12 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Mixtures and Solutions
- Replies: 2
- Views: 436
Re: Mixtures and Solutions
c is the concentration of solution, while n equals the mole of the matter and v equals the volume the solution.It's better to understand in this way, if you wanna know how matter is concentrated in the solution in the units of mole, you should divide the total amount of matter( in the unit of mole0)...
- Sun Oct 07, 2018 11:07 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Why amount of CH3CO2- doubled for each Ca(CH3CO2)2
- Replies: 4
- Views: 1095
Re: Why amount of CH3CO2- doubled for each Ca(CH3CO2)2
Cause if you wanna have Ca(CH3CO2)2, you have to have one Ca+ and two (CH3CO2) at the same time. so when you are going to calculate the concentration of ca(ch3co2)2, the concentration of ch3co2- must be two times of that of ca+
- Sun Oct 07, 2018 11:02 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Why doesn't a solute add to the volume of a solution? [ENDORSED]
- Replies: 6
- Views: 10985
Re: Why doesn't a solute add to the volume of a solution? [ENDORSED]
Compared to the volume of the solution, or to the solvent, the volume of your solute is so tiny; at the same time, the solute will dissolve in your solvent. So the solute will not account to the volume of a solution.
- Sun Oct 07, 2018 10:58 pm
- Forum: Significant Figures
- Topic: Number of significant figures when using Ka and Kb
- Replies: 2
- Views: 1230
Re: Number of significant figures when using Ka and Kb
I think you should depend your SF on other numbers, instead of Ka and Kb. Ka and Kb will change due to several factors.