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#1
"Calculate the mass in kg of a single 52Cr ion.
Assume the mass of a 52Cr ion is the same as that of a 52Cr atom
Avogadro Constant = 6.022 × 10 to the power of 23"

Can anyone please explain this to me?
I feel like its really simple but for some reason I'm just not getting it.
What's the equation I need to use?
0
2 years ago
#2
Do you know what the Avogadro constant represents?
0
2 years ago
#3
Mash the avocado with a fork in a shallow bowl until chunky. Season with fine salt and black pepper.
Toast the bread until browned and crisp. Lightly rub 1 side of each slice with the cut side of the garlic until fragrant; discard the garlic. Lightly brush the toasts with oil, and season with fine salt and pepper. Divide the mashed avocado evenly among the toasts, and top with more flaky sea salt, more black pepper and red pepper flakes if using.

Hope this helps!
1
2 years ago
#4
(Original post by Zoe Lea)
"Calculate the mass in kg of a single 52Cr+ ion.
Assume the mass of a 52Cr+ ion is the same as that of a 52Cr atom
Avogardo Constant = 6.022 × 10 to the power of 23"

Can anyone please explain this to me?
I feel like its really simple but for some reason I'm just not getting it.
What's the equation I need to use?
Atomic mass of Cr = 52.

1 mol of Cr = 52g
52g of Cr contains 6.02 x 10²³ atoms
Mass of one atom = 52/6.02 x 10²³

I've given you a full solution because when I did A-Levels I never saw this question, it was more of a simple Olympiad starter. Good luck anways
4
2 years ago
#5
(Original post by Kyber Ninja)
I never saw this question
It pops up on OCR A AS papers on a regular basis.
0
#6
(Original post by Pigster)
Do you know what the Avogadro constant represents?
No not really
0
2 years ago
#7
(Original post by Pigster)
It pops up on OCR A AS papers on a regular basis.
Ah, I did WJEC. I guess all exam boards have their favourite question types.
0
2 years ago
#8
(Original post by Kyber Ninja)
1 mol of Cr = 52g
52g of Cr contains 6.02 x 10²³ atoms
Mass of one atom = 52/6.02 x 10²³
Note, that the mass quoted here will be in grams, not kilograms as requested.
2
#9
(Original post by Kyber Ninja)
Atomic mass of Cr = 52.

1 mol of Cr = 52g
52g of Cr contains 6.02 x 10²³ atoms
Mass of one atom = 52/6.02 x 10²³

I've given you a full solution because when I did A-Levels I never saw this question, it was more of a simple Olympiad starter. Good luck anways
but why do you divide by the Avogadro constant?
0
2 years ago
#10
(Original post by Zoe Lea)
but why do you divide by the Avogadro constant?
First you divide 52 by 1000 to convert to KG
One mole of a substance is equal to its Mr in grams.
One mole of a substance also has Avogadro’s number of atoms.
Therefore one mole of Cr contains 6.022x10^23 atoms and weighs 52 g (or 0.052kg). So divide this by Avogadro’s number to find the mass of one of its atoms
2
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