A 7.30 g sample of pure NaHCO3 is heated strongly until it is completely decomposed: 2NaHCO3 -> Na2CO3 + CO2 + H2O. Using atomic masses H = 1, C = 12, O = 16, Na = 23, calculate the mass of CO2 released, in grams (two decimals).

JEE Main levelNumerical answerDifficulty 2 of 3pb066

A 7.30 g sample of pure $NaHCO X_{3}$ is heated strongly until it is completely decomposed: $2 NaHCO X_{3} Na X_{2} CO X_{3} + CO X_{2} + H X_{2} O$ . Using atomic masses H = 1, C = 12, O = 16, Na = 23, calculate the mass of $CO X_{2}$ released, in grams (two decimals).

Numerical answer type, answer in g, tolerance 0.01.

Molar mass of

NaHCO X_{3}

= 23 + 1 + 12 + 48 = 84 g/mol, so 7.30 g is 0.08690 mol. Two moles of

NaHCO X_{3}

give one mole of

CO X_{2}

, so

n (CO X_{2})

= 0.043452 mol. Mass = 0.043452 x 44 = 1.9119 g, i.e. 1.91 g.