A sample of 0.50 mol of 3-hydroxypent-4-ynoic acid, $HC \equiv C - CH (OH) - CH X_{2} - COOH$ , is treated with excess $CH X_{3} MgBr$ in dry ether. Assume that every active hydrogen (hydrogen on O of OH or COOH, and terminal alkyne hydrogen) liberates one $CH X_{4}$ and that the resulting carboxylate does not react further. What is the volume of $CH X_{4}$ in litres at STP (molar volume $22.4 L/mol$ ), to the nearest integer?

Numerical answer type, tolerance 0.5.

Answer: 34

Active hydrogens per molecule: one on the

COOH

, one on the alcoholic

OH

and one on the terminal alkyne carbon, total 3. Moles of

CH X_{4}

= 0.50 \times 3 = 1.5

mol. Volume

= 1.5 \times 22.4 = 33.6 L

, which is 34 L to the nearest integer.