Question

When silver combines with oxygen, a compound forms that contains 93.10% Ag by mass. What is the molecular formula of the oxide product if it is the same as the empirical formula?

Express your answer as a chemical formula.

Answer 1

hi, are you there? i can help you step by step if you'd like

Answer 2

yes < i am here

Answer 3

hi :-) So,have you already started or don't know where to start?

Answer 4

i do not know how can i solve ity actually

Answer 5

ok, no problem. Let's start by assuming we have 100 grams of the compound. So, how much Ag (silver) would we have?

Answer 6

(that helps a lot when they don't give an amount.... just assume an easy amount like 100 grams)

Answer 7

i do not know

Answer 8

100 grams * 93,1% = ?

Answer 9

9310

Answer 10

hehe almost.... it's a percent, right? so when we put it in the calculator, it looks different.

Answer 11

Try 100 * 0.931

Answer 12

93.1

Answer 13

yes, 93.1 grams. Ok good.
What is the other part of the compound?

Answer 14

oxygen??

Answer 15

exactly

Answer 16

So our compound is 100 grams. We have 93.1 grams of Ag (silver). How much oxygen must there be?

Answer 17

6.9??

Answer 18

exactly

Answer 19

Good. Do you have an idea how to figure out the next step?

Answer 20

may be i should multiply it by 2 because to formula AgO2?

Answer 21

No, this formula won't be AgO2 actually :-)

Answer 22

We can figure out what it is through the numbers though

Answer 23

Have you heard of or worked with moles yet?

Answer 24

yes

Answer 25

1moles = 6.02*10^23

Answer 26

that's right, good. We don't need that big number right now, thankfully. We need to know molecular masses (how much 1 mole of something weighs).

Answer 27

Where can you find molecular masses?

Answer 28

(for elements like silver, oxygen etc)

Answer 29

107.9 for Ag and 16 fot O
?

Answer 30

PERIODIC TABLE

Answer 31

Yes. How can we use the compound weights and the molecular weights to figure out moles?

Answer 32

1MOLE=16g of O?

Answer 33

exactly. And what about the 6.9 grams of oxygen? How many moles is that?

Answer 34

0.43?

Answer 35

Yep! And the silber? How many moles of silver?

Answer 36

*silver sorry

Answer 37

99.6?

Answer 38

i have a different number. How did you get that number?

Answer 39

100-0.43?

Answer 40

AHA

Answer 41

SORRY

Answer 42

I SHOULD DO LIKE THE LAST STIP

Answer 43

:-) unformtunately not so easy.
Tell me why this can't work:
100 grams - 0.43 moles

Answer 44

HAHA yes :-)

Answer 45

BECAUSE DIFFERENT WE CAN NOT DO CALCULATION IN GRAM AND MASS DIFFERENT UNIT

Answer 46

yes exactly. We have 0,43 moles of oxygen. So how many moles of silver?

Answer 47

(just like the last step like you said)

Answer 48

0.86

Answer 49

perfect.
0.43 moles of O
0,86 moles of Ag....
How can we get the empirical formula?

Answer 50

ADD THEM TOGETHER?

Answer 51

haha!! :-) no again not so easy
Why did we convert into moles?

Answer 52

Why are moles really useful?

Answer 53

I DO NOT KNOW

Answer 54

moles are a ratio

Answer 55

SO I SHOULD DIVIDE THEM?

Answer 56

When we have different weights, we can't say the formula because the weights of the elements are all different. But when we have moles, we can directly compare the amounts.

Answer 57

Yes

Answer 58

AHA , THIS IS A NEW INFORMATION THANK YOU

Answer 59

:-)

Answer 60

0.5?

Answer 61

Ok, 0.5 of what?

Answer 62

OF AgO?

Answer 63

nope... take a look at how I write it:

0.43 mol O
_________________
0.86 mol Ag

Answer 64

AFter doing the division, all 'units' cancel out except the elements, right?

Answer 65

YES

Answer 66

0.5 moles of _____ for every mole of _____

Answer 67

OF O FOR EVERY MOLE OF Ag?

Answer 68

exactly

Answer 69

So it would look really strange in the formula... AgO(0.5).... we need whole numbers

Answer 70

How to do that?

Answer 71

may be we should multiply it by the moles of Ag

Answer 72

? Maybe, but I can think of an easier way

Answer 73

We just need to get rid of the fraction
AgO(1/2)

Answer 74

multiply it by 2?

Answer 75

exactly

Answer 76

2AgO?

Answer 77

Not quite... 2 on the outside is very different from 2 on the inside of the fomula

Answer 78

You are almost there

Answer 79

1AgO??

Answer 80

INSIDE 1Ag and 2O?

Answer 81

IT IS NOT BALANCE

Answer 82

That#s right it'S not. Try thinking about it like this:

0.86 mol Ag
-----------
0.43 mol O

Answer 83

2 moles of Ag for every mole of O = 1 molecule of ________________

Answer 84

AgO

Answer 85

No.... 2 moles of Ag * 1 mole of O = Ag2O

Answer 86

(oops I mean + :-)

Answer 87

YES BECAUSE Ag i think it doesn't take 2

Answer 88

2 moles of o for every 1 mole of Ag

Answer 89

2 moles of O for every mole of Ag = 1 molecule of AgO2

Answer 90

IS THAT RIGHT?

Answer 91

What is the standard cation for Ag?

Answer 92

Ag^+

Answer 93

adnf oro?

Answer 94

ahhh sorry and for O?

Answer 95

O^2-

Answer 96

AHHHHHHHHHHHA

Answer 97

Ag takes +1

Answer 98

O takes -2