Answer to Question #84384 in General Chemistry for Darlene

Question

You need a total of 500,000 grams of fuel to make it back home. If you can produce 6.02X1025 molecules of H2 per hour, how many days will it take to refuel?

In the time it takes for your ship to refuel, how many liters of oxygen gas will you inhale to survive?

Answer 1

1. Find how many molecules of H₂ are in the 500,000 grams of fuel:

n=m/M

M(H₂) = 1.01*2 = 2.02 g/mol

n(H₂) = 500,000 g/2.02 = 247,525 mol

N(H₂) = n*N_A = 247,525 *6.022*10²³ = 1.49*10²⁹

Find how many hours will it take to produce 1.49*10²⁹ molecules of H₂

T(hours) = 1.49*10²⁹/6.02*10²⁵ = 2475.25 hours

As thre are 24 hours in a day then

T(days) = 2475.25/24 = 103.14 days

2. An average human needs 785.7 g of pure oxygen per day.

Find mass of oxygen consumed by a person during 103.14 days:

m(O₂) = 103.14 days*785.7 g/day = 81037.1 g

n= m/M

M(O₂) = 16.00*2 = 32.00 g/mol

n(O₂) = 81037.1 g /32.00 g/mol = 2532.4 mol

At STP molar volume V_m = 22.4 L/mol

V= V_m *n = 22.4 L/mol *2532.4 mol = 56726 L

Answer:

1. 103.14 days

2. 56726 L