[Aufbau89]

Concentrated sulfuric acid (18.4-molar H₂SO₄) has a density of 1.84 grams per milliliter.  After dillution with water to 5.20-molar, the substance has a density of 1.38 grams per millilter and can be used as an electrolyte in lead storage batteries for automobiles.

a) Calculate the volume of concentrated acid required to prepare 1.00 L of 5.20-molar  H₂SO₄.
b) Determine the mass percent of  H₂SO₄ in the original concentrated solution.
c) Calculate the volume of 5.20-molar  H₂SO₄ that can be completely reacted with 10.5 grams of sodium bicarbonate, NaHCO₃, in the reaction: 2NaHCO₃ +  H₂SO₄ -->  2H₂0  + Na_sSO₄ + 2 CO₂
d) What is the molality of the 5.20-molar  H₂SO₄?



Work

a) (5.20M)(1.00L)= moles  H₂SO₄
                         = 5.20 moles  H₂SO₄

   (5.20 moles)/(18.4M) = 0.28L  ?


-I'm sorry, this is a confusing chapter for me.  Can someone help me out with b,c, and d?  And was my A correct?  Sorry.  I really need help.

[Borek]

a. OK

b. Check http://www.chembuddy.com/?left=concentration&right=percentage-to-molarity - this is other way around, but you can easily solve final formula for C_%.

c. Simple stoichiometry. Start calculating number of moles of substance in 10.5 g of sodium bicarbonate.

d. This one is a little bit more tricky. Look at the definition of molality - assuming you have 1L of solution, how can you calculate number of moles of acid and mass of solvent?

[Aufbau89]

Ok thanks, I got it now.