Good G'Chem Q.

[dat_student]

We have 39.2% H2SO4 (by mass) in an aqueous solution whose specific gravity is 1.25. How many mili-liters of this solution is needed to make 100 ml of 0.2 M H2SO4. MW of H2SO4 = 98 g/mole.

 

[E. coli]

We have 39.2% H2SO4 (by mass) in an aqueous solution whose specific gravity is 1.25. How many mili-liters of this solution is needed to make 100 ml of 0.2 M H2SO4. MW of H2SO4 = 98 g/mole.

1.25 g/mL * 1000 mL = 1250 g of aqueous solution
39.2% * 1250 g = 490 g H2SO4
490 g H2SO4/ 98 g = 5 mole H2SO4
5 mole H2SO4 / 1 L = 5M H2SO4
0.1 L * 0.2 M H2SO4 = 5M * volume
volume = 0.004 L = 4mL of solution is needed

 

[dat_student]

1.25 g/mL * 1000 mL = 1250 g of aqueous solution
39.2% * 1250 g = 490 g H2SO4
490 g H2SO4/ 98 g = 5 mole H2SO4
5 mole H2SO4 / 1 L = 5M H2SO4
0.1 L * 0.2 M H2SO4 = 5M * volume
volume = 0.004 L = 4mL of solution is needed

correct

 

[joonkimdds]

We have 39.2% H2SO4 (by mass) in an aqueous solution whose specific gravity is 1.25. How many mili-liters of this solution is needed to make 100 ml of 0.2 M H2SO4. MW of H2SO4 = 98 g/mole.

where do u get these kind of questions? I don't remember learning about gravity stuffs during general chemistry 😛

 

[firenoodle]

1.25 g/mL * 1000 mL = 1250 g of aqueous solution
39.2% * 1250 g = 490 g H2SO4
490 g H2SO4/ 98 g = 5 mole H2SO4
5 mole H2SO4 / 1 L = 5M H2SO4
0.1 L * 0.2 M H2SO4 = 5M * volume
volume = 0.004 L = 4mL of solution is needed

should i feel ashamed if i dont know how to do this problem?? even worse, will i score very low on the DATs????

these types of problem common on the DAT??

 

[INFNITE]

i don't think you need to know specific gravity. I can't even find it in my chem textbook (McMurry & Fay). The only course i remember learning it from is Fluid Mechanics.