Recent content by reventon_703

Good day! I would just like to confirm a couple things in regards to my solution for this problem. Problem: A sample of hydrated ethanedioic acid crystals (formula H2C2O4 . 2H2O) of mass 0.2145g was dissolved in water and the solution was used to standardise some potassium permanganate...

Thanks for all the help, I really appreciated it! I am now able to solve this problem. NaIO3 + NaI + HCl -> NaCl + I2 + H2O 1+ 5+ 2- | 1+ 1- | 1+ 1- | 1+ 1- | 0 | 1+ 2- which I will rewrite as: NaIO3 + NaI + HCl -> NaCl + I2 + I2 + H2O Reduction : gain 5e-/NaIO3 Oxidation : lost...

Thanks for replying AGNuke. From my notes, I was told to use coefficients based on the electron transfer theory so that the number of electrons lost equals the number of electrons gained. So in the case of the above reaction, would one simply multiply 5 on both NaI and I2? But then this would...

Thanks for the quick reply Borek and JohnRC! Just as I thought so, so I shall proceed... NaIO3 + NaI + HCl -> NaCl + I2 + H2O 1+ 5+ 2- | 1+ 1- | 1+ 1- | 1+ 1- | 0 | 1+ 2- As shown from the oxidation number, I in NaIO3 has decreased its oxidation number from 5+ to 0, that means a...

Question Balance the following redox using oxidation number. Please show all steps. NaIO3 + NaI + HCl -> NaCl + I2 + H2O Attempted Solution So first I assigned oxidation number: NaIO3 + NaI + HCl -> NaCl + I2 + H2O 1+ 5+ 2- | 1+ 1- | 1+ 1- | 1+ 1- | 0 | 1+ 2-...

So how exactly is it easier? My teacher told me that, cos(/2-θ) = sinθ is easier to apply to an angle in 1st quadrant cos(/2+θ) = -sinθ is easier to apply to an angle in 2nd quadrant cos(+θ) = sinθ is easier to apply to an angle in 3rd quadrant cos(3/2+θ) = sinθ is easier to apply to an...

I had tried this over, and it is true that they work, but my question is really which one to use and why? Remember that you told me cos(θ+/2) = -sinx is an identity? So is cos(θ-/2) = sinx, but when would you use each? My teacher told me that you use the first one when you have an angle in...

[SIZE="4"] First of all, before I go on, I would like to thank everyone who had view this post or participate in helping with my problem. I had been trying to figure this out for 2 weeks and I had asked my teacher for at least 3 times, yet still in confusion. I have a test on Monday, I...

Thanks for replying Sammy. So, the following are identities but they are NOT cofunction identities? sin(x+pi/2) = cosx cos(x+pi/2) = -sinx tan(x+pi/2) = -cotx cot(x+pi/2) = -tanx csc(x+pi/2) = secx sec(x+pi/2) = -cscx In this case, my answer for this question would be cos(4pi/3) = sin(pi/2 -...

It turns out my data points were very close to the line of best-fit that passes through the origin, so problem solved. Thank you very much ehild!

Homework Statement Write the following in terms of the cofunction identity: cos(4pi/3) Homework Equations I know the θ is in Quadrant 3, but my question is, which cofunction identity am I suppose to use? Cofunction Identities: cosx = sin(pi/2 - x) #1 cosx = sin(pi/2 + x) #2...

Touche... it is hydrogen. But how can I find out if hydrogen gas is more reactive than copper? Gases are often more unstable and reactive than solids is it not?

Thank you for replying by ehild. I agree that there does exist some errors in conducting the experiment, I had mentioned them in my lab report. But since there exist these errors, would I still draw the straight line passing through the origin? In the lab outline, it asked us to calculate...

According to the reactivity series, copper is below hydrogen. In theory, hydrogen gas should be able to displace copper in a copper(II) chloride solution should the gas be bubbled into the solution, is this true?

Homework Statement An experiment was conducted where a slider with different mass combination is placed on a board. A Newton spring scale is attached to the slider and is pulled horizontally and parallel to the board such that the slider moves at a constant velocity. The applied force...