1.1. A hydrated salt, R, has the formula Na₂CO₃.xH₂O. 

Describe the chemical tests, including reagents and observations, that could be performed on the hydrated salt, R, to show that it is a sodium carbonate salt.

1.2. A sample of the hydrated sodium carbonate salt, R, was heated to a constant mass in a 92.200 g evaporating basin. Mass measurements were taken every five minutes and are shown in Table 1. 

Table 1

Determine the value of x in Na₂CO₃.xH₂O for the hydrated salt, R.

1.3. Explain the effect that not heating the salt to a constant mass will have on the value of x in Na₂CO₃.xH₂O.

1.4. Another hydrated salt, S, was analysed and found to have the following percentage composition by mass:

16.98% Ca; 11.86% N; 67.77% O; 3.39% H

Determine the empirical formula of the compound, showing clearly that it is a hydrated salt.