A student obtained 2.00 g of pure caffeine following recrystallization from a crude sample, which originally weighed 2.56 g. What is the percent recovery of pure caffeine from crude

78.125%

Explanation:

From the question, we are informed that a student obtained 2.00g of pure caffeine following recrystallization from a crude sample, which originally weighed 2.56g.

The percent recovery of pure caffeine from crude will be calculated as:

= Mass of pure caffeine / Mass of crude sample × 100

= 2.00 / 2.56 × 100

= 78.125%

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.