Need help in chemistry? plzzz board exams tomorrow?
Sulphur trioxide is prepared by the following two reactions: Cu2S +O2 ----> Cu2O + SO2 2SO2 + O2 ---> 2SO3 How many gram SO3 are produced from 159 grams of Cu2S( atmoic mass of Cu= 63.5, S=32, 0=16 gram/mol)? plz hurry and also show method.
Help!! Grade 12 Math!!! By Tomorrow?
1) (1+sin x) / cos x + cos x / (1+ sin x) = (1+sinx)² + cos²x /cosx*(1+sinx)= (1+2*1*sinx+ sin²x + cos²x) /cosx*(1+sinx)= As sin²x+cos²x = 1: (1+2*sinx+ 1) /cosx*(1+sinx)= (2*sinx+ 2) /cosx*(1+sinx)= 2*(sinx+ 1) /cosx*(1+sinx)= 2 /cosx= 2*(1/cos x) = 2 sec x 2) (sinx +tan x) / (1+ cos x) = 1/ cot x (sinx +tan x) / (1+ cos x) = (sinx +(sinx/cosx)) / (1+ cos x) = ((sinx*cosx +sinx)/cosx) / (1+ cos x) = ((sinx*cosx +sinx)/cosx) *1/(1+ cos x) = (sinx*cosx +sinx)/ (cosx*(1+cosx)) = (sinx*(cosx +1))/ (cosx*(1+cosx)) = sinx/ cosx = As cotx = cos x / senx: 1/cot x 3) sec ^2 x / ((sec^2 x) - 1) = csc ^2 x sec ^2 x / ((sec^2 x) - 1) = sin²x +cos²x = 1 Dividing by cos²x: sin²x/cos²x +cos²x/cos²x = 1/cos²x tan²x + 1 = sec²x tan²x = sec²x -1 sec ^2 x / ((sec^2 x) - 1) = sec²x / tg²x = (1/cos²x) / (sin²x/cos²x) = (1/cos²x) * (cos²x/sin²x) = (1/sin²x) = csc²x 4) sinx[cos^2x]+sin^3x = sinx (cos²x+sin²x) = sinx*1 = sinx As csc x = 1/sin x: =1/csc x Kisses from Brazil =**
It's my exam tomorrow and I am unable to concentrate. I don't feel like studying and I am disturbed. What are some suggestions on what to do?
It's the exact situation I'm going through right now and here's what I'm going to do:-I'll close my books and just stare at the wall for 5–10 minutes.This will clear my mind of any thoughts.I'll go for a walk and just observe the things happening around.This will energize my body and will refresh my mind.I'll sit on my table and list down all the points on ‘ Why is it important to score good in this examination?’.This will provide me with all the positive motivation I need.I'll open my books and will go through the questions that are more probable to come.This will help me recollect things I've already studied.I'll write bullet points of the important topics to be seen before entering the examination hall.This will give me confidence when I enter the examination hall the next day.I'll have a sound sleep of minimum 6 hours and will set up an alarm of 5 AM.This will provide my mind and body the rest it needs.I'll check all the necessary stationaries and my admit card and finally doze off.This will save me from the hassle in the morning and I'll reach my examination centre on time.P.S. : All the best..!!