Question

How many atoms of hydrogen are in 220g of hydrogen peroxide (H2O2)?

This is what I did so far:

the molecular weight of H2O2 = 2*1 +2*16 =34

therefore, there are 220/34 moles of the molecule = 6.47 moles, so there are 6.47xAvogadro's number of molecules

there are 2 H atoms per molecule, so multiply 2x6.47x(6.02e^23) which is 7.591084947e^11
but for some reason it is wrong

Answer 1

I bet it is.
2*6.47*6.02E23 is nowhere near anything times E11.
Goodness. You are off by a factor of at least 1E12

Answer 2

Now, I'm getting 4870.270527 when I insert these values (2)*(6.470)*(6.02e^23)...is there any another way that i can insert theses into the calculator?

Answer 3

paste this into the google search window:

2*6.470*6.02E23

You need to learn how to be friends with your calc.

Answer 4

Sorry again to be pain in the neck...but this is what i got 2 * 6.47000 * 6.02E23 = 7.78988 × 1024...it is still wrong...this is driving me crazy

Answer 5

All I see is that the number of significant digits needs to be reduced, I would go to two, but the units need to be specified (grams). Did the idiot computer expect kilograms?

Answer 6

yes, it does. I tired all the combination but IT DOESN'T WORK. I am about to give up on this problem

Answer 7

If it expects kilograms, then 7.8E21kg

Answer 8

wait one sec:

I didn't catch your error.

You divide by avagradro's number

2*6.47*6.02E23 NOT
2*6.47/6.02E23 Should be this.
divide molmass by avagradro's number to get mass of one molecule.

Answer 9

(2 * 6.47000) / 6.02E23 = 2.14950166 × 10-23...oh my god it is still wrong...

Answer 10

Seeing this student struggling for six hours with one question and is still getting it wrong is funny but I also feel the pain.

Answer 11

I know it's been almost a decade since they last posted but I know some people are struggling so here is how you're going to do it.
n=M(in grams)/Mmol [The equation to the first step]
The molar mass of Hydrogen Peroxide is = 1(2)+16(2) = 34g/mol
[1 is the atomic mass number of hydrogen multiplied by 2 because it's H2]
[16 is the atomic mass number of oxygen x 2 since it's O2]
According to the equation we have to divide the mass by the Molar mass
= 190g/34g/mol=5.59 moles
Then you will multiply it by 2 since it's H2 = 11.18
Then you will multiply it by Avogadro's number
According to the equation N=nNa (Na is Avogadro's number)
= 11.18 (6.02x10^23)= 67.3 x 10^23
=6.73 x 10^24