Question

In an experiment to find the formula of the oxide formed of the element M, 5.5g of M was burnt in oxygen. The mass of the oxide was 8.7g

What is the formula of the metal oxide?

Answer 1

@Callisto sorry...

Answer 2

\[M+O_2--->MO\]
M=5.5g
MO=8.7g
\[8.7g-5.5g=3.2g O_2\]

Answer 3

I got MO2

Answer 4

So which metal have you predicted?

Answer 5

they are just asking the formula, with "M"

Answer 6

If it is MO2, then it's probably a group II metal... but I can't find it!!! (Sorry.. starving and must eat something now...)

Answer 7

If metal + oxygen , it must be 2MO or M2O otherwise the charges wouldn't cancel
\[2M+O2−−−>2MO\]

\[4M+O2−−−>2M2O\]


Unless it is transition metal

Answer 8

Why can't it be M2O3? Like Al2O3 (even though it doesn't seem like to be the answer :|)

Answer 9

So... is RAM of M = 55?

Answer 10

RAM = relative atomic mass
I think you missed some data given in the question, right?

Answer 11

@zaphod

Answer 12

Firstly, what's the equation to solve this problem? Is it:
xM+(y/2)O2---->MxOy...??

Answer 13

It's difficult to solve that in that way.... :(
Perhaps insufficient information.

Answer 14

Yups.. I agree @Callisto

Answer 15

If in that way,
no. of mole of O2 used
= (8.7-5.5)/(16.0x2) = 0.1mole
y/2 = 0.1 => y=0.2

For no. of mole of M:
5.5/m = x

For no. of mole of MxOy:
8.7 / (xm+16.0y) = 1
8.7 / (5.5 + 16.0x0.2) =1
1=1
._.

Answer 16

If the question is this, then it's easy ._.
In an experiment to find the formula of the oxide formed of the element M, 5.5 g of M was
burnt in oxygen. The mass of the oxide was 8.7 g.
[Ar: M, 55; O, 16.]
What is the formula of the metal oxide?

Then,
no of mole of M = 5.5/55 = 0.1mole
no. of mole of O2 = (8.7-5.5) / (16.0x2) = 3.2/32 = 0.1 moles

Since the mole ratio of M:O2 = 0.1/0.1 = 1:1
So the formula of metal oxide is MO

Answer 17

Note: I just googled this question and find that it's one of the question in UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS - General Certificate of Education Ordinary Level (October/November 2004)
It's question 7

Answer 18

but the answer is MO2, give me the link

Answer 19

yeah but the answer says its MO2

Answer 20

:O Wait... let me check my answer again...Sorry!

Answer 21

okay

Answer 22

it should be O ----> not O2

Answer 23

Wait?! What do you mean?

Answer 24

The stupid problem of mine I've found is that....
Ratio of M:O2 = 1:1
So, the formula is MO2 ._.
M + O2 -> MO2

Answer 25

the oxygen
M + O ---->
5.5/55 + 3.2/16 --->
0.1 + 0.2
0.2/0.1 --->2 Oxygen

MO2.......AM i right

Answer 26

No... oxygen gas is O2...

Answer 27

Hey I got the MO2.. Wait.. I'll post my working..

Answer 28

okay..

Answer 29

no of mole of M = 5.5/55 = 0.1mole
no. of mole of O2 = (8.7-5.5) / (16.0x2) = 3.2/32 = 0.1 moles

Since the mole ratio of M:O2 = 0.1/0.1 = 1:1
So the formula of metal oxide is MO2
M + O2 -> MO2

My bad :|