asking for a teacher's opinion
Do you think rounding borderline letter grades up or down is a fair practice? Or should they just stay where they are? For example, I think that an 89.5% should round up to a 90%. I have one instructor right now who considers an 89.99% to still be a B plus. It seems a bit asin...
If motor M exerts a force of F=(10t2+100)N on the cable, where t is in seconds, determine the velocity of the 25kg crate when t=4s . The coefficients of static and kinetic friction between the crate and the plane are μs=0.3 and 0.25 μk=0.25 . The crate is initially a...
A spherical balloon has a radius of 11 centimeters. If we increase the radius by 2 centimeters, how much did the volume increase?
Thank you very much!
I did the next problem, i don't have the results for it and i just want to know if i calculated the mass for Fe2O3 the right? A sample is a mixture of iron oxides (Fe2O3 and FeOOH). It's known that at 200°C this reaction occurs: 2FeOOH(s)-> Fe2O3(s) + H2O(g) A 0...
What is a pH of 20 mL of 0.08 M NH3 added to 40 mL of 0.04 M HCl? NH3 + HCl = NH4+ + Cl- c(NH3)=(0.02L * 0.08M)/0.06L= 0.02667 M c(HCl)=(0.04L * 0.04M)/0.06L= 0.02667 M c(NH4+)=c(HCl) Kb=[NH4+][OH-]/[NH3] Kb=1.76*10^(-5) So i tried to calculate it like this: Kb=[OH-] pOH=4.754...
you will have to use this two formulas p*V=n*R*T n=m/M p*V=(m/M)*R*T p*V*M=m*R*T M=(m*R*T)/P*V then just make sure you convert units right (i hope i did convert them right, if not then correct me) M=(0.311g*8.314L kPa*328.15K)/(mol*K*118.124 kPa*0.225L) M=31.924 g/mol
NaHCO3 + HCl -> NaCl + CO2 + H2O n(NaHCO3)=n(HCl) n(NaHCO3)=m/M=2.3g/83.99*(g/mol)=0.027384 mol m(HCl)=n*M m(HCl)=0.027384 mol * 36.46 (g/mol)= 0.9984 g
First of all, thank you so much for answering and i'm sorry for writting all the problems at once. I won't do that anymore in the future. #5 i was looking at the different problem with my result, that's why i wrote the concentration :S #9 thank you, i just realized...
Below i wrote a few problems, i did them all but in the book i don't have results, so i don't know if i did them right or not. I would really appreciate if someone would go through the problems and tell me if i got the right results. If i made a mistake somewhere pleas...