What is 0.3 liters?
it means the weight or the volume of the liquid is 0.3 litres which is equivalent to 300mililitres.
What is the resulting concentration of Na When 70 milliliter of 3 molar Na2CO3 is added to 30 milliliters of 1 molar NaHCO3?
You have .07 Liters of 3 moles/Liter of Na2CO3. So if you do .07*3*2 (you multiply by two because there are TWO Na+ ions in Na2CO3) you get .42 moles of Na+. Then you do the same with NaHCO3. So, .03*1 is equal to .03 moles of Na+. Adding .42 with .03 will give you .45, the number of moles of Na+ of the whole solution. Since you are looking for concentration (which is moles…