Question

Which of the following samples has the greatest mass?
A)1.4 mol Na
B) 1.02 × 1024 atoms Na
C) 23 g Na
D) 6.02 × 1023 atoms Na

Answer 1

@ganeshie8

Answer 2

@whpalmer4

Answer 3

@ParthKohli

Answer 4

i want to change it to grams

Answer 5

but i don't know how

Answer 6

Ah, I see.

First of all, you know that one mole is 6.022 x 10^23 in quantity.

Answer 7

yes

Answer 8

So B is 2 mol of Na.

Answer 9

ok

Answer 10

1 mol of Na is 23 g. 2 mol is?

Answer 11

ok

Answer 12

46g

Answer 13

Good. B is 46 grams.

Answer 14

Let's analyze A before we calculate the mass.

Obviously, it's not gonna be the answer because B is 2 moles which is greater than A. So we're not gonna continue with it. Do you see why?

Answer 15

oh yeah, but how did you get 2 mole of Na?

Answer 16

and yes

Answer 17

in B? see how.

1 mol is 6.022 * 10^23
2 mol is approximately 1.02 * 10^24

Answer 18

ok

Answer 19

...?

Answer 20

what happened

Answer 21

sorry hehe.

C is 23 grams which is less than the 46 we calculated, so it obviously won't be the greatest either.

Answer 22

yes

Answer 23

how about D? how many moles is that?

Answer 24

4?

Answer 25

how did you get that?

Answer 26

how did you approximately calculate for B?

Answer 27

one mol is 6.02 * 10^23, right?

what would be two times that?

Answer 28

2

Answer 29

Oh

Answer 30

;P

Answer 31

right. how about D now?

Answer 32

so 1 mol of Na, is 23 right?

Answer 33

right, 23 grams.

how many moles is D?

Answer 34

46 again?

Answer 35

wait no

Answer 36

how do you find it out?

Answer 37

D is 6.02*10^23 atoms of Na

Does that number ring a bell? It should — it's the number of items in a mole. How much does a mole of Na atoms weigh?

Answer 38

ok

Answer 39

22.989?

Answer 40

about that, yep!

Answer 41

So the answer would be B right?