CIa and 32% ()-tartaric acid. Ar unknow Compound weighing.4.2 gm is dissolved in enough carbon tetrachloride to make a total volume of 250 c.c. The observed rotation of this solution is +357.75° in a 25 cm cell using the solium D line. But if 4.2 gm is dissolved in 125 ce we observed rotation is +355.50°.Calculate Spr cific rotation for this compound. 9.