Chemistry Question?

Question

I am studying for a chemistry final and having trouble with this type of problem. Can someone please show me how to work out this problem.

How many moles are there in 17.5 g of H2SO4. Any help would be greatly appreciated.

Answer 1

moles = mass / formula mass

formula mass = the sum of the atomic wieghts of the thing in question. 2 Hygrogens at one each is 2, plus one sulphur at 32.1 (or 32) = 32 , four oxygens at 16 each is 64

all together that is 98 or 98.1
mass = 17.5
mass / formula mass = 17.5 / 98 = 0.178 moles of H2SO4

By the way, what year of school is this for?

Answer 2

Look up the elements on the periodic table.

H - 1.00794
S - 32.066
O - 15.9994

Take each of these elements and multiply by the number of each.

H - 1.00794 x 2 = 2.01588
S - 32.066 x 1 = 32.066
O - 15.9994 x 4 = 63.9976

Now add them together.

98.07948

This is the molecular mass of the compound.
In other words, there are 98.07948 grams per mole

Now, divide the number of grams by the molecular mass.

17.5 / 98.07948 = 0.178426720859...

Lastly, there are 3 significant figures.

Answer: 0.178 moles H2SO4

Answer 3

so simple
no of moles=mass in gram/relative molecular mass
=17.5/2+32+64
=17.5/98
=0.1785moles
u plz check calculation again
otherwise everything is right

Answer 4

H2SO4, so that means there are 2 atoms of hydrogen, 1 atom of sulfur, and 4 moles of oxygen, therefore

2 atoms of hydrogen is 2x 1.0 (where do i get 1.0? go to your periodic table and look at the molar mass of hydrogen)= 2.0
1 atom of sulfur is 1x 32.1= 32.1
4 moles of oxygen= 4x16.0=64.0

then add them all, so 2.0+32.1+64.0=98.1grams per mole ( this number is the mass of one mole of sulfuric acid (H2SO4 is sulfuric acid)

17.5 grams x 1 mole = 0.178 moles(the grams cancelled out)
----------------
98.1 grams
i really hope my explanation is clear enough. coz it's really hard to explain it here. anyways, hope u understand it. see ya.

Answer 5

I gave this question to my girlfriend who has a B.S. in Chemistry and she says 0.178 moles H2SO4

Answer 6

i dont get it but if u get the answer will u tell me and show me how to work it out