Question

please solve this problem by step by step plz ​

Answer 1

Answer:

Lets first pretend that you said at least 500. mL (to three significant digits). Use the unit-factor method (aka dimensional analysis). If you aren’t familiar with the unit-factor method, then you need to fix that since it is very useful in solving a wide range of chemistry problems.

The solution is based on the general knowledge that 1 mole of any ideal gas at STP occupies a volume of 22.414L. In addition, we know that 1 mol of anything is 6.022x10^23 anythings, that is, Avogadro’s constant: 6.022x10^23 mol⁻¹.

0.500L x (6.022x10^23 molecules O2 / 22.414 L) = 1.34x10^22 …… the answer is rounded to our pretend precision of three significant digits.