Question

A commercial refrigeration unit accidentally releases 7.68x10^1 mL of ammonia gas at SATP. Determine the mass and number of ammonia molecules released.

Answer 1

Answer: -

0.0583 g and 2.064 x 10²⁰ molecules of ammonia are released when a commercial refrigeration unit accidentally releases 7.68 x 10¹ mL of ammonia gas at STP

Explanation: -

Volume of ammonia gas released = 7.68 x 10¹ mL

= 76.8 mL

= $\frac{76.8 }{1000}$

= 0.0768 L

We know that at STP standard temperature and pressure,

22.4 L of a gas has 6.02 x 10²³ molecules of ammonia.

0.0768 L of a gas is occupied by $\frac{6.02 x 10^23 molecules x 0.0768 L }{22.4 L}$

= 2.064 x 10²⁰ molecules of ammonia

Molar mass of NH₃ = 14 x 1 + 1 x 3 = 17 g.

At STP, we know

22. 4 L of ammonia has 17 g of ammonia.

0.0768 L of ammonia has $\frac{17g NH3 x 0.0768 L}{22.4 L}$

=0.0583 g of ammonia.

∴ 0.0583 g and 2.064 x 10²⁰ molecules of ammonia are released when a commercial refrigeration unit accidentally releases 7.68 x 10¹ mL of ammonia gas at STP