Answer
$$968 mols$$
Work Step by Step
Divide masses provided by the molecular mass of the molecule/element to find the mols.
Molar mass of $C_2H_2 = 2\times(12.01, mass of carbon) + 2 \times (1, mass of hydrogen) = 26.02 g$
$\frac{25200g C_2H_2 in sample}{26.036gC_2H_2 per mole} \approx 968mol C_2H_2$
