How many atoms are in 167 g of calcium?

2 Answers
Apr 18, 2018

remind that mass=number of moles x molar mass and molar mass of Ca is 40
167=n*40167=n40
n=4.175n=4.175
1 moles =6.02 × 10^23 6.02×1023atoms
therefore 4.1752 moles of Ca=4.175*6.02 × 10^23 4.1756.02×1023=2.51335× 10^24 2.51335×1024atoms

Apr 18, 2018

m=167gm=167g
M(Ca)=40.078g/(mol)M(Ca)=40.078gmol

Explanation:

n=m/M=167g/(40.078 g/(mol))=4.167 moln=mM=167g40.078gmol=4.167mol
nn-numbers of mol

N=n*N_a=4.167 mol*6,022 × 10^(23)N=nNa=4.167mol6,022×1023 (atoms)/(mol)
=25*10^(23)=251023 atoms

N_aNa- Avogadro's constant=6,022 × 10^(23)=6,022×1023 (atoms)/(mol)