1.1. The concentration of a solution can be measured in different ways.

Which are the correct units for concentration in terms of the mass of a solid dissolved in a known quantity of liquid? 

Circle the correct answer. 

1.2. A student is asked to make a sodium hydrogen carbonate solution, NaHCO₃ (aq).

The student uses 0.25 moles of sodium hydrogen carbonate.

Calculate the mass of sodium hydrogen carbonate that the student uses. 

Relative atomic masses (A_r):     C = 12;     H = 1;     Na = 23;     O = 16 

1.3. What is the concentration of the student's solution in g / dm³?

1.4. The student takes a 25 cm³ portion from their 1 dm³ sodium hydrogen carbonate solution. 

There are 1000 cm³ in 1 dm³. 

Estimate the mass of sodium hydrogen carbonate in the 25 cm³ portion.