Question

1. How many grams are there in 7.5 x 1023 molecules of H2SO4?

Answer 1

Answer:

I cannot give you all the answer but I can help you to solve those.

Explanation:

The first question:

How many grams are there in 7.5×$10^{23}$ molecules of $H_{2} SO_{4}$?

So we need to find the molecular mass first, use your periodic table,

And then we can find out 2+32+16×4=98 g/mol

Then, we need to find how many moles, by using Avogadro's constant:

Avogadro's constant: 1 mole = 6.02×$10^{23}$

∴$\frac{7.5*10^{23} }{6.02*10^{23}}$=1.25 mol(2d.p.)

Lastly, find the grams using the formula $M= \frac{m}{n}$

m=Mn

m=1.25*98

m=122.5g

-------------------------------------------------------------------------------------------------------------

In conclusion, use those formula to help you:

$M= \frac{m}{n}$ (which M = molecular mass(atomic mass) m=mass of the substance and n = moles)

Avogadro's constant: $\frac {molecular mass} {6.02*10^{23}} = moles$