How many formulas units are in 3.11 mole of Ca(NO3)2 can you show your work by step by step correct answer

18.73× 10²³ formula units

Explanation:

Given data:

Number of moles of Ca(NO₃)₂ = 3.11 mol

Number of formula units = ?

Solution:

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"  

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

Number of formula units of Ca(NO₃)₂:

1 mole contain 6.022 × 10²³ formula units

3.11 mol ×  6.022 × 10²³ formula units / 1 mol

18.73× 10²³ formula units

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.