Question

What is the mass in grams of 7.5 x 10^15 atoms of nickel?

Answer 1

Atomic mass Ni = 58.69 a.m.u

58.69 g ----------------- 6.02x10²³ atoms
?? g --------------------- 7.5x10¹⁵ atoms

58.69x (7.5x10¹⁵) / 6.02x10²³

=> 7.31x10⁻⁷ g

Answer 2

Answer:

The mass of $7,5.10^{15}$ nickel atoms is $7,34.10^{-7}g$ grams

Explanation:

We want to know how many grams $7.5.10^{15}$ nickel atoms equals and we know that one mole of any substance equals 6.021023 atoms

To know how many moles correspond $7.5.10^{15}$ nickel atoms apply a simple rule of three

$6,02.10^{23} atoms\longrightarrow 1 mol\\7,5.10^{15} atoms\longrightarrow x\\x=\frac{(7,5.10^{15})(1mol) }{6,02.10^23atoms} \\x= 1,25.10^{-8} mol$

The constant that relates the mass (grams) and the amount of substance (mol) is the molecular mass of the element The nickel molar mass is 58.69g/mol

to know how many grams of nickel correspond $1,25.10^{-8} mol$ mol we apply a rule of three simple

$1 mol \longrightarrow 58.69 g\\1,25.10^{-8}\longrightarrow x \\x= \frac{(1,25.10^{-8}mol)(58.69g) }{1mol} \\x=7,34.10^{-7}g$

The mass of $7,5.10^{15}$ nickel atoms is $7,34.10^{-7}g$ grams