Suppose that a 0.2 g/ml solution of (s)-ibuprofen in a 2 dm long cell rotates plane-polarized light +10°. what is the specific rotation for (s)-ibuprofen?

+25°

Explanation:

The formula for calculatin the specific rotation, α, is:

α=αobs÷(c×l)

αobs being the rotation observed

c is being the concetration(g/mL)

l being the path length(dm)

So it ends up being:

α=+10°/(0.2 g/mL×2 dm)= +10°×ml/0,4g×dm

α=25°

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error