nitric acid is composed of HNO3 molecule.A sample of 4.50 g was obtained. calculate the number of oxygen atom in the sample.
this is what i do .can u check if i am wrong or miss something
answer : mole HNO3 = 4.50g/63 = 0.07 mol
mole : no of particle/NA
= 0.07x (avogardo constant)
= 4.214 x 10^22
no of oxygen atom is = 4.24 x 10^22 x 3 = 1.26 x 10^23
2 answers
method is correct and I agree with the aritmetic
Your process is correct and the answer would be correct but you threw away part of the answer in the 0.07. You're allowed 3 significant figures by the 4.50 so you don't round the 0.0714 answer you should have obtained to 0.07. In fact, I like to keep one extra place and round to the proper number at the final answer.
3 answers