Question

How many grams of nitric acid will react completely with a block of iron metal that is 4.5 cm by 3.0 cm by 3.5 cm, if the density of iron is 7.87 g/mL? Show all steps of your calculation as well as the final answer.

Fe + HNO3 → Fe(NO3)3 + H2

Answer 1

@Abhisar i need some assistance please

Answer 2

Can u do the question if i tell how many grams of iron is given ?

Answer 3

sorry i dont understand

Answer 4

i mean i don't understand the question you are asking

Answer 5

What part is giving u trouble in this (original question) question ?

Answer 6

i don't know how to solve the question. i do know that i first must balance the equation so i did, I came up with Fe2O3 + 6HNO3 yields 2Fe(NO3)3 + 3H2O. Then i don't know what to do after that.

Answer 7

All ryt let's seee !

Answer 8

First tell me the atomic masses of Fe, O, H & N

Answer 9

Fe: 55.845 ± 0.002 u
O: 15.9994 ± 0.0004 u
H:1.00794 ± 0.00001 u
N: 14.0067 ± 0.0001 u
like do you personal memorize the atomic mass or is it okay to look at a periodic table. Because i looked up the atomic masses.

Answer 10

wait i forgot where are the atomic masses located next to the element?

Answer 11

It's okay to look at the periodic table, but i personally remember atomic masses of common elements.

Answer 12

oh ok

Answer 13

How u balanced ur equation ?

Answer 14

Given equation is Fe + HNO3 → Fe(NO3)3 + H2 and ur balanced equation is Fe2O3 + 6HNO3 yields 2Fe(NO3)3 + 3H2O.

Answer 15

Getting it ?

Answer 16

i don't understand how to balance the equation.

Answer 17

Balanced equation will be
2Fe + 6HNO3 → 2Fe(NO3)3 + 3H2

Answer 18

Getting it ?

Answer 19

U can't change the reactant or product side for balancing the equation !
U changed Fe into Fe2O3

Answer 20

u can only add coefficients like 2Fe, 4Fe or whatever is needed

Answer 21

oh my bad!

Answer 22

Got it ?

Answer 23

yes i do.

Answer 24

Now from the balanced equation \(\large \sf 2 Fe + 6 HNO_3 = 2 Fe(NO_3)_3 + 3 H_2\) we can see that 2 moles (111.69 g) of Fe will react completely with 6 moles of nitric acid (378.07704 g).

Answer 25

sorry but where are you get the 2 moles of Fe?

Answer 26

So for 1 g of iron \(\huge\sf \frac{378.07}{111.69}\) = 3.38 g of Nitric acid will be required.

Answer 27

Got it ?

Answer 28

oh oopss that was obvious, yes i got it.

Answer 29

Now we know that how much of nitric acid is required for each gram of iron. All we have to do now is to calculate the amount of iron in the block of iron.

Answer 30

agree ?

Answer 31

yes

Answer 32

So let's do it..Though it's not absolutely correct but we will have to assume that 1cm\(^3\) of iron = 1mL

Answer 33

So density of iron becomes 7.87 g/cm\(^3\)

Answer 34

Now what will be the volume of iron block ?

Answer 35

i don't really get it. So is it something like this: 7.87= 1 ml???

Answer 36

Don't see the above lines, just calculate the volume of the iron block by using this

Volume = Length\(\times\)Breadth\(\times\)Height

Answer 37

Dimensions are given as
4.5 cm
3.0 cm
3.5 cm,

Answer 38

Volume=4.5\(\times\)3\(\times\)3.5=47.25

Answer 39

yes i was think that but i was sure!

Answer 40

Volume=4.5\(\times\)3\(\times\)3.5=47.25 cm\(^3\)

Answer 41

Given density of iron is 7.87 g/cm\(^3\) which means that 7.87 g of iron is present in 1 cm\(^3\). Can u tell me how much grams will be in 47.25cm\(^3\) ?

Answer 42

6.004???

Answer 43

7.87\(\times\)47.25 = ?

Answer 44

oh you have to mult.? i divide oops so it is 371.8575

Answer 45

Now remember what we calculated earlier ?

\(\color{blue}{\text{Originally Posted by}}\) @Abhisar
So for 1 g of iron \(\huge\sf \frac{378.07}{111.69}\) = 3.38 g of Nitric acid will be required.
\(\color{blue}{\text{End of Quote}}\)

Answer 46

yes

Answer 47

Now for 371.8575g of iron how much nitric acid will be required ?

Answer 48

should I multiply 371.8575 X 3.89?

Answer 49

obvsly !

Answer 50

sorry i am not the brightest person, i got 1,446,52568

Answer 51

\(\color{blue}{\text{Originally Posted by}}\) @superhelp101
should I multiply 371.8575 X \(\cancel{3.89}\) 3.38
\(\color{blue}{\text{End of Quote}}\)

Answer 52

Got it ?

Answer 53

eh. then the answer is 1256.87835. wow i can't believe how one decimal point makes such a big difference to the answer.

Answer 54

Yep !
Copy carefully :)

Answer 55

and u were wrong !
u r the brightest person around here, even brighter than me !

Answer 56

http://prntscr.com/41ub83

Answer 57

What? Yayy. You made my day even though even though it is like 1:00am. Lol how come on my screen it shows that i only have 64 points?? that that is weird?

Answer 58

\(\huge\color{green}{\text{¯\_(ツ)_/¯}}\)

Answer 59

did you edit the snapshot?? to make it look like i had 99 points?

Answer 60

Ahahahahhahaha that is sooooooo funny

Answer 61

^_^