One mole of hydrogen gas burns in excess of oxygen to give 290 kJ of heat. What is the amount of heat produced when 4g of hydrogen gas is burnt under the same conditions ?

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Q: 92 (IAS/1994)
One mole of hydrogen gas burns in excess of oxygen to give 290 kJ of heat. What is the amount of heat produced when 4g of hydrogen gas is burnt under the same conditions ?

question_subject: 

Science

question_exam: 

IAS

stats: 

0,46,69,10,26,46,33

keywords: 

{'hydrogen gas burns': [0, 1, 0, 0], 'hydrogen gas': [0, 0, 1, 2], 'heat': [10, 3, 13, 46], 'mole': [1, 1, 1, 4], 'oxygen': [3, 0, 1, 0], 'kj': [0, 1, 1, 1]}

To determine the amount of heat produced when 4g of hydrogen gas is burnt, we can use the concept of molar mass and stoichiometry.

Given:

1 mole of hydrogen gas (H?) burns to give 290 kJ of heat.

Step 1: Calculate the number of moles of hydrogen gas in 4g:

The molar mass of hydrogen (H) is 1 g/mol. Since hydrogen gas (H?) has two atoms of hydrogen, its molar mass is 2 g/mol.

To calculate the number of moles, we divide the given mass by the molar mass:

Number of moles = mass / molar mass

Number of moles = 4g / 2 g/mol

Number of moles = 2 mol

Step 2: Calculate the heat produced for 2 moles of hydrogen gas:

Given that 1 mole of hydrogen gas produces 290 kJ of heat, we can calculate the heat produced for 2 moles:

Heat produced = 290 kJ/mol * 2 mol

Heat produced = 580 kJ

Therefore, when 4g of hydrogen gas is burnt under the same conditions, the amount of heat produced is 580 kJ.

So, the correct answer is 580 kJ.