# Chemistry question

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#1
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#2
Help needed in this question.
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2 years ago
#3
(Original post by abdullahAK)
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Would say answer C. Look at the educts: the amount of oxygen is five times greater than propane. Thus the volume of oxygen has to be five times higher than propane that they react each other to the products carbon dioxide and water.
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2 years ago
#4
Answer is C. C is correct because both propane and oxygen are gases and we can apply Avogadro's law.

A is wrong. Since propane and oxygen are gases at standard conditions, we can apply Avogadro's law. 10 cm3 of propane requires 50 cm3 of oxygen gas for complete combustion. If the volume is less than 50cm3, we get an incomplete combustion of propane and produce gases such as carbon monoxide. Hence, it is wrong to state that propane CANNOT burn. It will burn but the burning (combustion) is incomplete.

B is wrong. H2O is a liquid based on the state symbol given and hence, we cannot apply Avogadro's law. Option B is correct only if H2O is a GAS.

D is wrong. Assuming that the gaseous reactants are used in stoichiometric amount, 10 cm3 of propane + 50 cm3 of oxygen = initial volume of the gases. After combustion, the only gas left is the carbon dioxide and its volume is only 30 cm3. There is a REDUCTION in volume of 30 cm3 (50 + 10 - 30 = 30). We only consider the volume of gases and not liquid.
(Original post by abdullahAK)
Help needed in this question.
Last edited by David Tan; 2 years ago
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