Answer:
0.004522 moles of hydrogen peroxide molecules are present.
Explanation:
Mass by mass percentage of hydrogen peroxide solution = w/w% = 3%
Mass of the solution , m= 5.125 g
Mass of the hydrogen peroxide = x
![w/w\% = \frac{x}{m}\times 100](https://tex.z-dn.net/?f=w%2Fw%5C%25%20%3D%20%5Cfrac%7Bx%7D%7Bm%7D%5Ctimes%20100)
![3\%=\frac{x}{5.125 g}\times 100](https://tex.z-dn.net/?f=3%5C%25%3D%5Cfrac%7Bx%7D%7B5.125%20g%7D%5Ctimes%20100)
![x=\frac{3\times 5.125 g}{100}=0.15375 g](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B3%5Ctimes%205.125%20g%7D%7B100%7D%3D0.15375%20g)
Mass of hydregn pervade in the solution = 0.15375 g
Moles of hydregn pervade in the solution :
![=\fraC{ 0.15375 g}{34 g/mol}=0.004522 mol](https://tex.z-dn.net/?f=%3D%5CfraC%7B%200.15375%20g%7D%7B34%20g%2Fmol%7D%3D0.004522%20mol)
0.004522 moles of hydrogen peroxide molecules are present.
Answer:
a pencil being sharpened
freezing water
boiling water
Explanation:
a physical change doesn't change the chemical structure of an object. That is why the other 2 are wrong