Recent content by CroSinus

1. Homework Statement A circle in a x-y coordinate system is given. The equation of the circle is unknown. The circle touches the x axes at (3,0). It also passes through the point B (0,10). Calculate the length of the circle radius? Homework Equations (x-p)^2 + (y-q)^2 = r^2 The Attempt at a...

Thank you once again for dealing with my chemistry problems. Yes, "per mole of a reaction as written", to my thinking, that is the right interpretation of the unit kJ / mol. If I want to calculate the amount of energy (heat) released in a reaction when ΔrH° is given, should I use the formula: q...

Thank you for your swift answer. :-) I do not know about digits. Should I write only 1249.1 kJ / mol? The confusing thing is the unit: kJ per mol. Per mol of what?

1. Homework Statement The chemical reaction is given: 2C2H2 + 5O2 -> 4CO2 + 2 H2O. ΔrH* = -1299 kJ / mol. How much heat is released when 50 grams of C2H2 is burned? Homework EquationsThe Attempt at a Solution First, I convert mass into moles. M(C2H2) = 2*12+2 = 26 g/mol n(C2H2) = m/M = 50 g...

Homework Statement Name the following alcane according to the IUPAC rules: Homework EquationsThe Attempt at a Solution Thank you for helping me! Cro

Strange rules. Would not be better if I took into consideration all substituents? In other words shouldn't I pay attention to the sum of all substituents? Well, strange rules! Thank you for helping me. Cro

Well, it appears to be the chain number (2), OR (3). Is there a place where I can find all the important rules for naming alkanes in one location? Thank you for your help. CroSinus

Homework Statement Name the following compound according to the IUPAC rules: Homework EquationsThe Attempt at a Solution Help me with the answer, please!

Homework Statement Name the following compound according to the IUPAC rules: Homework EquationsThe Attempt at a Solution Comment on my attempt, please.

For example: mass of water is given and amounts to 18 g. Calculate the number of moles for water molecules, and calculate the number of moles for hydrogen atoms. Answer: m (H2O) = 18 g n (H2O) = ? n (H) = ? ------------------------------------- n (H2O) = m (H2O) / M(H2O) = 18 g / 18 g mol-1...

I do not understand your question. Molar mass simply represent the mass of one mole of entities. These entities could be anything: atoms, molecules, whatever...

I think I used an adequate definition formula for pH: pH = - log (H+). Since HCl is a strong acid I assumed that c(HCl) = c(H+). Thank you very much for your help, Cro

Are you trying to tell me that a water solution with such a high molarity (4.41 M) is not possible? Thank you very much, CroSinus

Homework Statement Hello everybody, How can I calculate pH value of 4.41 M HCl water solution? Is it possible for such a solution to exist? Thank you very much for your help, CroSinus Homework EquationsThe Attempt at a Solution When I try to find - log 4.41 I get a negative value. I do not...

Thank you very much Borek for trying to help me. The answer from my textbook says: V(O2) + V(H2) = 169,2 dm3