Answer:
a. 0.18 mol
b. 1.084 x 10²³ atoms
Explanation:
Data Given:
mass of gold (Au) = 35.12 g
a. number of moles of gold (Au) = ?
b. number of atoms of gold (Au) =?
Solution:
Part a:
To find number of moles following formula will be used
no. of moles = mass in grams / molar mass . . . . . . (1)
molar mass of gold (Au) = 197 g/mol
put values in equation 1
no. of moles = 35.12 g / 197 g/mol
no. of moles = 0.18 mol
so. number of moles of Au = 0.18 mol
_________________
Part b:
To find number of atoms following formula will be used
no. of moles = no. of atoms / Avogadro's number
Rearrange the above equation
no. of atoms = no. of moles x Avogadro's number . . . . . . . (2)
Avogadro's number = 6.022 x 10²³ atoms /mol
put values in equation 1
no. of atoms = 0.18 mol x 6.022 x 10²³
no. of atoms = 1.084 x 10²³
so.
number of atoms of Au = 1.084 x 10²³ atoms
Answer:
Explanation:
Given data:
Mass of gold = 35.12 g
Number of moles of gold = ?
Number of atoms of gold = ?
Solution:
A) Number of moles:
Formula:
Number of moles = mass/ molar mass
Molar mass of gold = 197 g/mol
Number of moles = 35.12 g/ 197 g/mol
Number of moles = 0.18 mol
B) Number of atoms:
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 .
One mole = 6.022 × 10²³ atoms
0.18 mol × 6.022 × 10²³ atoms / 1mol
1.084 × 10²³ atoms of gold
