Question

help with a calculation?

It's an assignment of, like, 50 questions and I just need help with one or two calculations. I'm currently failing my class and got a 60% on this assignment last time I turned it in. I'm not asking for much, I just need HELP.

technically, this is a chemistry calculation, but I can't get help in that section so I wanted to ask here. I have all the needed numbers, I just have no idea how to get to the answer.
I just need a step-by-step explanation as to how to properly find the answer so I'll be able to do this by myself in the future.

3. Determine the number of moles of NaOH.
105 mL NaOH * 1L NaOH / 1000 mL NaOH * 0.50 mol NaOH / 1L NaOH = ?

Answer 1

chemistry hmm

Answer 2

yeah, not a lot of people help there and I'm clueless on solving this so I thought someone in math would have a background in chem enough to help.

Answer 3

@SolomonZelman

Answer 4

@Hero @KyanTheDoodle @ShadowLegendX

Answer 5

Oh, the Sam Hunt fangirl

Answer 6

O_____O

I don't know what to do here.

Answer 7

I don't either, I'm clueless. My mom is yelling at me to get it done, but I can't seem to get any help and I can't find any way to understand this.

Answer 8

I'm not even sure how to define what the question is asking. I looked up molarity because I thought that may be it but I'm honestly so confused on everything in chemistry.

Answer 9

@jabez177

Answer 10

@jhonyy9

Answer 11

look please i have got it now this

Quickly convert grams NaOH into mole using the molecular weight calculator and the molar mass of NaOH. ... How many grams NaOH in 1 moles? The answer is 39.99711. ... 1 grams NaOH is equal to 0.0250018063805 mole.

Answer 12

again try this website please - hope will help you

http://www.convertunits.com/from/grams+NaOH/to/moles

Answer 13

But I don't think I started out with grams anywhere?

Answer 14

In the lab I did to get those calculations, I had 105 mL of NaOH. We never measured in grams.

Answer 15

so but you know that 1 Liter = 1 kilogram = 1000 gramm - ok ?

Answer 16

Oh, okay.
So, step by step, can you walk me through how it changes the calculations to find the answer?

Answer 17

you have wrote above that you wan,like to know just the way how you can convert it and how you can getting the right answer - so this is the way - hope will help you

Answer 18

Okay.

Answer 19

But, humor me here: we start with 105 mL NaOH * 1L NaOH / 1000 mL NaOH * 0.50 mol NaOH / 1L NaOH.
What is the first step, what do we change first? Do we convert the liters into the grams?

Answer 20

so than you not can getting it i m here so than try tag me back and i will try help you again
ok. ?

Answer 21

I'll try it, sure.

Answer 22

first step you know that 1 liter equal 1000 mL - yes
and you know that 1 liter = 1 kilogram = 1000 grams

Answer 23

If I immediately change the liters into grams to moles, the equation looks like this:
105 mL * 25 mol / 1000 mL * 0.50 mol / 25 mol

Is that right?
Can we change the 1000 mL on the bottom of the first half to 1 liter and then to grams and then to moles?

Answer 24

@jhonyy9

Answer 25

If I DO change the 1000 mL to liters to grams to moles:
105 mL * 25 mol / 25 mol * 0.50 mol / 25 mol

We can cancel out all the 25 mol so
then there'd just be 105 mL * 0.50 mol left?

And would it be multiplied or divided?

Answer 26

That kind of feels off to me, but I don't know so

Answer 27

please use parentheses on these equation because i dont understand it right - what are numerator and denominator - thank you

Answer 28

Ah, I can do that.

So:
([105 mL * 25 mol] / 1000 mL) * (0.50 mol / 25 mol)

Answer 29

That's the calculation after converting the liters to grams to moles ^

Answer 30

But, humor me here: we start with 105 mL NaOH * 1L NaOH / 1000 mL NaOH * 0.50 mol NaOH / 1L NaOH.
What is the first step, what do we change first? Do we convert the liters into the grams?

so than you see it here above why 1 liter from numerator dont simplifie with 1000 mL from denominator - or i dont see it right ?

Answer 31

When you cancel out, you have to do them cross-wise, right?

Answer 32

please rewrite it without NaHO and use parantheses

Answer 33

([105 mL * 1L] / 1000 mL) * (0.50 mol / 1L)

Answer 34

so from the first fraction 1 Liter by 1000 mL cancel out - or not ?

Answer 35

If you can transfer the mL into L or vice versa... I think they could? I'm a little fuzzy on the rules for canceling out - it's been a while since I've actively used them.

Answer 36

I know they have to be the same unit to cancel.

Answer 37

ok. but than you can converting 1 liter in 1000 miliLiter so than you will see it right - yes ?

Answer 38

so cancel them out and write me please what will reamain there

Answer 39

([105 mL * 1000 mL] / 1000 mL) * (0.50 mol / 1L)
(105 mL) * (0.50 mol / 1L)? I think that's what you asked, at least.

Answer 40

@jhonyy9

Answer 41

Okay, alternatively, I did it this way. Tell me if any of this looks right.

What I did before was taking the original equation:
([105 mL * 1L] / 1000 mL) * (0.50 mol / 1 L)
Cancel out the liters and the mL
([105 * 1] / 1000) * (0.50 mol / 1)
(105 / 1000) * (0.50 mol / 1)
105 * (0.5 mol / 1000) = 0.0525 moles NaOH