Search found 18 matches

by Martin
Thu Mar 09, 2017 10:59 am
Forum: Chemical Projects
Topic: Acid-Base Theories
Replies: 0
Views: 1956

Acid-Base Theories

Hello, could someone explain the different acid-base theories and their uses?

I heard about a few theories, including the arrehenius acid base theory, bronsted-lowry theory, and lewis theory, and was wondering about their different aspects and significances.
by Martin
Thu Mar 09, 2017 10:54 am
Forum: Chemical Projects
Topic: What is the concentration of 2% starch?
Replies: 0
Views: 935

What is the concentration of 2% starch?

I am doing a lab report that asks what the concentration of 2% starch is and I do not know how to answer. please help. I think it was a 5ml solution if that helps. I do not know how to solve so I cannot provide any work. I measured the weight of one drop of starch (0.038g)
by Martin
Thu Mar 09, 2017 10:51 am
Forum: Chemical Projects
Topic: Electrolysis of KBr
Replies: 0
Views: 1202

Electrolysis of KBr

Use the standard reduction potentials to determine what is observed at the cathode during the electrolysis of a 1.0 M solution of KBr that contains phenolphthalein. What observation(s) is(are) made? O2(g) + 4 H+(aq) + 4 e– :rarrow: 2 H2O(l) E° = 1.23 V Br2(l) + 2e– :rarrow: 2 Br–(aq) E° = 1.07 V 2 H...
by Martin
Thu Mar 09, 2017 10:47 am
Forum: Chemical Projects
Topic: Methane Stoichiometry
Replies: 0
Views: 965

Methane Stoichiometry

Methane is a very powerful greenhouse gas. One pound of methane traps 25 times more heat in the atmosphere than a pound of carbon dioxide. Methane is also the main ingredient in natural gas. Because methane can be captured from landfills, it can be burned to produce electricity, heat buildings, or p...
by Martin
Thu Mar 09, 2017 10:46 am
Forum: Chemical Projects
Topic: Decreasing pH of a reaction at equilibrium
Replies: 129
Views: 7561

Decreasing pH of a reaction at equilibrium

Pb(s) + PbO2(s) + 4H+(aq) + 2SO42–(aq) ⇌ 2PbSO4(s) + 2H2O(ℓ) Assuming equilibrium has been established, which one of the following will cause a decrease in pH? (a) adding more solid lead (b) adding solid sodium sulfate (c) removing solid lead sulfate (d) adding barium nitrate solution I am assuming ...
by Martin
Thu Mar 09, 2017 10:42 am
Forum: Chemical Projects
Topic: iodine diffusing to an area of higher concentration?
Replies: 0
Views: 946

iodine diffusing to an area of higher concentration?

My biology class recently did an experiment in which we mixed 4ml of glucose and 4ml of starch in a bag made of dialysis tubing (a synthetic selectively permeable membrane), and submerged it in a beaker containing an iodine solution (200ml of distilled water mixed with 0.8ml of iodine), to see what ...
by Martin
Thu Mar 09, 2017 10:41 am
Forum: Chemical Projects
Topic: dilute of HNO3
Replies: 0
Views: 1045

dilute of HNO3

Hello guys Please excused my english skills. I am from germany. Currently I try to dilute or better create a 0,1 mol/l HNO3 acid. My parent substance is a 53% HNO3 whitout other data. I need to run a electrolysis a 0,1 mol/l HNO3. Maybe my chemestry skills are very low, althougt I have a degree in a...
by Martin
Thu Mar 09, 2017 10:34 am
Forum: Chemical Projects
Topic: Why do different isomers have a different enthalpy of combustion?
Replies: 0
Views: 1028

Why do different isomers have a different enthalpy of combustion?

I did an experiment in class and found that different isomers gave me different enthalpies of combustion. Why is this? I used Butan-1-ol, Butan-2-ol, 2-methylpropan-1-ol and 2-Methylpropan-2-ol.

Thanks.
by Martin
Thu Mar 09, 2017 10:31 am
Forum: Chemical Projects
Topic: Calculating molecular formula from emperical formula without molar mass
Replies: 150
Views: 5031

Calculating molecular formula from emperical formula without molar mass

Got this as a practice exam question. 4.31 g of a compound of carbon, hydrogen and nitrogen contains 2.68 g of carbon and 1.04 g of nitrogen. The compound is a base and one mole of it reacts with two moles of hydrochloric acid. In a typical titration, 0.1174 g of the compound was just neutralised by...
by Martin
Thu Mar 09, 2017 10:08 am
Forum: Chemical Projects
Topic: Help Please! Redox Reactions!
Replies: 0
Views: 903

Help Please! Redox Reactions!

Quickly wondering

What is oxidized and what is reduced as well as how many electrons are gained/lost by the elements in this redox reaction?
2H2 + O2 --> 2H2O + energy