Mole concept 1
To keep fit, an astronaut needs to burn 34.2 grams of sucrose
C
X
1
2
H
X
2
2
O
X
1
1
per hour in his body. How many grams of oxygen would the astronaut need in a space shuttle, in order to burn the sucrose to have enough energy for 1 day?
Image Credit: Wikimedia NearEMPTiness .
The answer is 921.6.
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1 solution
342g of sucrose contains 176g of oxygen. Therefore 34.2 g contains 17.6g of oxygen. This 17.6g of oxygen supplies emergy for 1 hour. 24 hrs require 24x17.6 g of oxygn = 422.4g of oxygen.
This may be the correct answer.
wait, why have you taken 12? isn't the molecular mass of oxygen 16?
Doesn't it takes 3 Mol of Oxygen to fully react ( oxidize) 1 mol of sucrose ? 34.2 g of sucrose is 0.1 Mol . Hence it takes 0.3 mol of Oxygen to fully combust a mole of sucrose. 0.3 mol of oxygen is 4.7998 grams. in 24 hours, he would need 4.7998 * 24= 115.19 grams of oxygen.
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Why only 3 mol? What is your chemical equation?
C 1 2 H 2 2 O 1 2 + 3 O 2 =
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Yeah it takes 12 mols of Oxygen to fully combust 1 mol of sucrose. 34.2 g of sucrose contains 0.1 mol. Therefore it will take 1.2 mols of O2 which turns out to be 1.2 * 31.9988=38.398 g. In 24 hours that is equivalent to 921.56
So the answer is correct.
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Edit
Why have you multiplied 16 by 3? should not it be 12 * (16 * 2 ) ?
342 g sucrose needs 1 2 × ( 1 6 × 2 ) oxygen in 1 hour.
34.2 g sucrose needs 1 2 × ( 1 6 × 2 ) ÷ 1 0 oxygen in 1 hour.
oxygen needed for 24 hours is 2 4 × 1 2 × ( 1 6 × 2 ) ÷ 1 0 = 9 2 1 . 6 0 g .