Question

What is true if mass is conserved in a reaction?
A) There are more atoms on the reaction side.
B) There are more atoms on the product side.
C) The number of atoms on each side changes.
D) There are equal numbers of atoms on both sides.

Answer 1

I am not sure if I have to close a question after its been answered

Answer 2

Generally people like to say 1 question / post (so they can harvest more medals :P), but you don't really have to for me.

What do you think the answer is? :)

Answer 3

I think its C it just makes more sense in my head but I might be wrong

Answer 4

So when mass is conserved, it means no mass is destroyed. e.i. the same amount of mass or atoms if you will must be present on both sides of the reaction.

Answer 5

so is it D then?

Answer 6

Correct.

Answer 7

Oh okay thank you

Answer 8

If anything appear strange, just speak up, then we can discuss it so you can get a better understanding :)

Answer 9

Okay thanks :) I have more questions if you could help me...? I feel really bad asking but this is stressing me out so

Answer 10

Better to ask for help than to fail right?

Answer 11

Well. it is not really cheating when you try come to the answer your self bases on clues and explanation of theory. And so long you understand why the answer is correct I would say it is fine.

Answer 12

based*

Answer 13

Okay I dont know if I should just put questions here or make new questions for each problem...?

Answer 14

As I said it is kinda up to you. We can just a few more here.

Answer 15

Okay
Thank you :)

Answer 16

What reaction would the chemical equation CH4 + 2O2 --> 2H2O + CO2 represent?
A) replacement of methane.
B) decomposition of methane.
C) combustion of methane.
D) formation of methane.

Answer 17

Well I feel like I have to know the formula for methane...

Answer 18

if there is one

Answer 19

Methane is CH4 right?

Answer 20

Correct.

Answer 21

H is hydrogen and O is oxygen?

Answer 22

Yup and C is carbon.

Answer 23

Do I have to figure out what 2 hyrdogen and 2 oxygen make? I feel like that might be irrelevant

Answer 24

It is kinda irrelevant. This question is more to figure out what kind of reaction this is.

Answer 25

oh

Answer 26

Have you heard about the different kinds of reactions?

Answer 27

CO2 is carbon dioxide right?
and I think so I just dont remember very well

Answer 28

CO2 is carbon dioxide yes.
Alright lets go through the reactions:
Replacement: is a reaction in which one element is substituted for another element in a compound.
Decomposition: Is the deformation of the compound by it self to form other molecules.
Combustion: is the reaction with oxygen to form water and carbon dioxide.
Formation : is the creation of a compound from other molecules (right hand side of the reaction)

What do you think the answer is based on the info you have been given?

Answer 29

I think it might be Combustion I am seeing 2H2O and H2O is water and CO2 is carbon dioxide and from the information you gave me thats what it looks like

Answer 30

so C

Answer 31

I might be wrong though

Answer 32

That is correct! :)
It is basically what happens when you burn coal for example. Coal reacts with the oxygen in the air at high temperatures (why you need fire) to produce water and carbon dioxide. Same principle when you add fire to a helium gas. :)

Answer 33

Oh thank you! I cant believe I actually did that XD

Answer 34

In the reaction , Al2O3 + 6 HCL --> _________H2O + 2AlCl3, what coefficient should be placed in front of H2O to balance the reaction
A) 1
B) 2
C) 3
D) 6

Answer 35

I learned this not to long ago

Answer 36

Time to do some calculations. Remember what I said about the law of mass conservation. The same amount of atoms must be on the same side of the equation. :)

Answer 37

okay

Answer 38

Okay wait so the left side is 11 or 5 and 6?

Answer 39

Try look at hydrogen only.
How many water molecules do you need on the right side to be equal the amount of hydrogen on the left side?

Answer 40

I am seeing 2 hyrdogen on the right side...

Answer 41

True. So if you could place a number in front of \(\sf H_2 O\) what would you place? :)

Answer 42

2?

Answer 43

I was so focused then my dogs started barking now I have lost concentration

Answer 44

I'm confused

Answer 45

So when you write:
\(\large \sf H_2 O\) there are 2 hydrogen.
\(\large \sf 2~H_2 O\) there are 2*2=4 hydrogen
\(\large \sf 3~H_2 O\) there are 3*2=6 hydrogen.

You see the tendency? :)

Answer 46

Yes

Answer 47

So if you could place any number in front of H2O like I just did. What number would you place for the numbers of hydrogen to be the same on both sides? :)

Answer 48

oh wait is it 6?

Answer 49

I am seeing 2,3 on both sides and then 6 in the middle so would it be 6 because then wouldnt it be the same?

Answer 50

wait

Answer 51

I lied

Answer 52

its H2O

Answer 53

I just confused myself

Answer 54

Al2O3 + 6 HCL: left side.
x H2O + 2AlCl3: right side.

How many hydrogen on left side? :)

Answer 55

6?

Answer 56

Correct. How many on right side? :)

Answer 57

would it be 6?

Answer 58

in H2O I am seeing 2 oxygen and it doesnt say how many hydrogen...?

Answer 59

There is only 2 atm. when there is no number in front of H2O then x=1

Answer 60

oh

Answer 61

What number is x equal to if you need 6 hydrogen on the right side?

Answer 62

I thought that would be 4?

Answer 63

How many hydrogen do you get if you have \(\sf 4~H_2O\)?
(sorry I am draging you through this, but it is really important you can do these kind of things as this is essential to chemistry)

Answer 64

I'm sorry I feel really bad that you have to put up with me

Answer 65

So when you write a number in front a molecule it say how many times you have that specific molecule.

Answer 66

okay

Answer 67

is it 3?

Answer 68

correct. The answer is 3. Show me why.;)

Answer 69

is it like multiplying? 3x2 is 6 so each side would be multiplied to six?

Answer 70

Yeah, that is completely correct! What about oxygen? Is there the same amount of those on both sides?

Answer 71

yes

Answer 72

I think so

Answer 73

How many are the on both sides? :)

Answer 74

2?

Answer 75

Ahh a little more.

Answer 76

Take a good look.

Answer 77

3?

Answer 78

Correct. :)

Answer 79

Oh okay! I understand now thank you!

Answer 80

I am only on 12 of 30 :/ this is stressing me out

Answer 81

So I fast made a similar problem you could solve it? ;)

Answer 82

Okay

Answer 83

Actually. Lets do this some other time. You have a lot of questions. We better go through those. Then I can always help you train equation balancing some other day.

Answer 84

Okay :)

Answer 85

Which of these statements explains the relationship among elements, compounds, and mixtures?
A) Compounds are made of mixtures, and mixtures are made of elements.
B) Mixtures are made of elements, and elements are made of compounds.
C) Both compounds and mixtures are made up of elements.
D) Elements are made of compounds and mixtures.

Answer 86

Haha. Such a funny question. What do you think? :)

Answer 87

B

Answer 88

or A

Answer 89

Not quite.

Think lemonade ;)