[DividebyZero]

Just want to check this to make sure... if you have 35% conc. of an acid, and you want 150ml of 5% what would the calculation look like?

A 6% conc of a soln. from a solid would simply be 100mL + 6 grams of the solid?  Or would it be mg?

Also, any solution of ~36% is 11M correct?

edit: for the acid conversion I just divided 35/5 = 7.  So 7 parts water for 1 part acid?  Meaning 129mL of H2O and ~21.4 mL of acid.  Is this correct?

[Borek]

A 6% conc of a soln. from a solid would simply be 100mL + 6 grams of the solid?

Np, it will be 6 grams of solid in 100 grams of the solution.

Also, any solution of ~36% is 11M correct?

No. 36% is around 11M if it is hydrochloric acid. In the case of sulfuric acid it is about 4.7 M.

For the correct result you have to take into account mass of the solute and mass of the solvent. And don't go for volume unless you know the density of the solution.