Question #c5870

2 Answers
Sep 12, 2017

2.0201023 atoms

Explanation:

First, convert grams of chromium to moles:

17.441g Cr(1 mol51.996 g Cr)=0.335 mol Cr

Then convert from moles to atoms using Avogadro's Number:

0.335mol Cr(6.022*10^23 atoms1 mol)=2.0201023 atoms Cr

Sep 12, 2017

Number of chromium atoms2×1023

Explanation:

We work out (i) the molar quantity of chromium....

Moles of Cr = 17.441g51.9961gmol1

=0.3354mol.

And (ii) we know that a mole specifies Avogadro's number of molecules, i.e. 6.022×1023mol1, and so we take the product....

=0.3354mol×6.022×1023mol1=??