Question 6

6.1 Methyl propanoate is an organic compound with the following percentage
composition:

54,55% C ; 9,09% H ; 36,36% O

The molar mass of the compound is 88 g∙mol^-1.

6.1.1 Define the term empirical formula. (2)

6.1.2 Determine, by calculation, the empirical formula. (6)

6.1.3 Determine the molecular formula. (2)

6.2 Learners prepare a solution of sodium hydroxide (NaOH) in water by placing
8 g of sodium hydroxide (NaOH) in a volumetric flask and adding water to
produce 250 cm³ of solution after stirring.

6.2.1 Define concentration in words. (2)

6.2.2 Calculate the concentration of the sodium hydroxide (NaOH) solution. (4)

6.3 Sodium azide (NaN₃) is used in car airbags. For the airbag to inflate the following reaction must take place:

2 NaN₃ (s) → 2 Na (s) + 3 N₂ (g)

Calculate the volume of nitrogen gas (N₂) that would be produced at STP if
55 g of sodium azide reacts completely. (5)

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