Question

okay so i have 2 questions pertaining to stoichiometry, is anyone willing to help. i will fan and medal

Answer 1

@escamer are you good with chem?

Answer 2

im sorry but i dont know this ;-;

Answer 3

its cool, but thanks for looking

Answer 4

np :)

Answer 5

Ok, so first, do you know the order of conversions?

Answer 6

no im not familiar with that, i just started this class @snackshack79

Answer 7

alright, I'm fairly new to this too.

the order of conversions is going to be
grams > moles > moles > grams

Answer 8

okay so like i have to turn grams to moles, and back?

Answer 9

real quick, how much do you already understand?

do you understand the cross cancellation that has to take place?

Answer 10

yeah, i know that, and i know i have to make the chart. i also know Tripotassium phosphate (K3PO4) has a Molar mass approx: 212.27 g/mol

Answer 11

well lets focus on the first one first

Answer 12

do you know what to start with?

Answer 13

okay so for that one, i need to make the chart that looks like this right?

Answer 14

well, I Learned it a bit differently

first your going to need to start with 42.0 g Na2O

Answer 15

and thats the molar mass?

Answer 16

so do you know how to convert it to moles?

Answer 17

yes. i can convert to moles

Answer 18

alright, how?

Answer 19

42 g Na2O x (1 mol Na2O / 62 g) = 0.6774 mol Na2O, 62 is the molar mass, of the compound

Answer 20

this is where i got stuck

Answer 21

alright, that looks good so far, but there's going to be more to the equation. next we need to convert from moles of sodium oxide to moles of sodium

Answer 22

so this step is going to be

(x mol Na / y mol Na2O)

Answer 23

do you know what x and y are going to be?

Answer 24

y is gonna be 0.6774 mol Na2O right?

Answer 25

nope, the x and y values are both in your balanced equation

Answer 26

4 and 2?

Answer 27

exactly!!!

Answer 28

and we multiply by the .6774?

Answer 29

so, so far we have:

42 g Na2O x (1 mol Na2O / 62 g) (x mol Na / y mol Na2O)

we are going to need to multiply in one more of these fractions, and then we'll be done

Answer 30

oops, sorry, I meant:

42 g Na2O x (1 mol Na2O / 62 g) (4 mol Na / 2 mol Na2O)

so, now we're going to convert it back to grams, this time grams of sodium (Na)

Answer 31

0.6774 mol Na2O x (4 mol Na / 2 mol Na2O) = 1.3548 mol Na, i think

Answer 32

and that 1.3548 mole is 31.16 grams of Na

Answer 33

alright, that looks good, but I'm going to need to see that last step between moles of Na and grams of Na

Answer 34

31.16 grams of sodium?

Answer 35

alright, what is the fraction you used to get 31.16?

Answer 36

do you want me to be honest? i just put 1.3548 mol converted to grams in google

Answer 37

alright, that's fine, but your going to need to know this conversion:

x g Na / 1 mol Na

Answer 38

any idea what replaces the x?

Answer 39

so 42g Na/ 1 mol Na?

Answer 40

no, for any conversion between grams and moles, there will be 1 mol, and the grams will be the molar mass of the molcule

Answer 41

ohhhh so......23 g?

Answer 42

yep, so can we put the whole equation together, so we can solve the whole thing?

Answer 43

this is what i got on my paper,

convert the 42 g of Na2O into mol.
42 g Na2O x (1 mol Na2O / 62 g) = 0.6774 mol Na2O

how many mol Na are needed to produce 0.6774 mol Na2O.
0.6774 mol Na2O x (4 mol Na / 2 mol Na2O) = 1.3548 mol Na
convert the mol Na into grams.

1.3548 mol Na x (23g Na / 1 mol Na) = 31.16 grams Na

therefore, 31.16 grams of Na are needed to produce 42.0 grams of Na2O.

is this correct?

Answer 44

Perfect!!!

Answer 45

so can you help me as i go through the last one?

Answer 46

sure

Answer 47

wait! i just found something in my note book! 1 mole K2PO4 yields 3 moles KNO3

Answer 48

that's what the balanced equation is saying too

Answer 49

this one's easy, its just mole to mole

Answer 50

so do i multiply that ratio by 2.5 to get my answer?

Answer 51

pretty much, but can you tell me the equation you're supposed to use?

Answer 52

ummm 2.5mol of Potassium phosphate (1 mole K3PO4/ 3 moles KNO3)

Answer 53

and you get 7.5 mol?

Answer 54

not quite, you got the right answer, but your fraction's upside down

Answer 55

so what should it look like?

Answer 56

2.5 mol K3PO4 ( 3 moles KNO3 / 1 mole K3PO4)

Answer 57

ohhh okay, thank you so much! and i may definitely be needing your help in the future

Answer 58

alright, if I'm on I'll certainly help you if you tag me