Two mole questions for Chemistry...?

Question

1. Determine the mass of 0.50 moles of table salt (NaCl).
2. How many atoms are contained in 0.55 mole of calcium metal?
Can anybody teach this to me? Thanks!

Answer 1

1) 0.50 mol x 58.44gm/1 mol NaCl = 22.99 gm

2) 0.55 mol x 6.022 x 10^23 atoms/1 mol = 3.312 x 10^23 atoms of Ca. ---> I think, double check.

Answer 2

ok stoicheometry is the technique needed here, if you have .5 moles of NaCl you multiply that by the converstion factor of Grams/moles of NaCl

for the second part you use the moles/atoms conversion factor, which is 1mol/6.02x10^23atoms

the first conversion factor is 1mol/Grams in one mole of NaCl i think its 28 but im not sure check the periodic table

ill check back if you add any questions

Answer 3

1. Find the atomic weights of Na and Cl and add together to get molecular weight. mass = 0.50 X molecular weight

2. 0.55 X Avogadro's number

Answer 4

Use conversion factors. ie. moles--> g/moles for the first and moles--> 6.022x10^23 atoms/mole for the second. Hope this helps!