Question #f1e48 Chemistry 1 Answer ec ยท Aditya Banerjee. Oct 16, 2017 25 g of Na_2SO_4 is required. Explanation: C % = ("mass of solute") /("mass of solute"+"mass of solvent") Let, rarr mass of solute (Na_2SO_4) = x rarr mass of solvent (water)= 100g C %= x/(x+100)*100%=20% Hence the equation becomes: x=(x+100)*0.2 x=0.2x+20 0.8x=20 x=20/0.8 x=25g. (Answer). Hope it Helps:) Answer link Related questions How do I determine the molecular shape of a molecule? What is the lewis structure for co2? What is the lewis structure for hcn? How is vsepr used to classify molecules? What are the units used for the ideal gas law? How does Charle's law relate to breathing? What is the ideal gas law constant? How do you calculate the ideal gas law constant? How do you find density in the ideal gas law? Does ideal gas law apply to liquids? Impact of this question 1168 views around the world You can reuse this answer Creative Commons License