Answer:
15.06 × 10²³ atoms of Li
Explanation:
Given data:
Number of moles of Li = 2.5 mol
Number of toms of Li = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen
For 2.5 mol of Li:
1 mole of lithium = 6.022 × 10²³ atoms of Li
2.5 mol × 6.022 × 10²³ atoms of Li / 1 mol
15.06 × 10²³ atoms of Li
Answer:

Explanation:
Regardless of the type of gas, 1 mole at standard temperature and pressure (STP) occupies a volume of 22.4 liters. In this case the gas is helium (He).
We can set up a ratio.

Multiply by the given number of moles.

The moles of helium will cancel.


Multiply.

5.25 moles of helium gas at STP is 117.6 liters of helium.
Distillation is a process of separating the component substances from a liquid mixture by selective evaporation and condensation.
Answer:
Oxygen's atomic weight is 16.00 amu. 1 mole of oxygen is 6.02 x 1023 atoms of oxygen 1 amu = 1.661 x 10-24g What is the molar mass (g/mole) of oxygen? Molar mass (in grams) is always equal to the atomic weight of the atom! Molar mass (in grams) is always equal to the atomic weight of the atom!