The tea was no longer hot or (brewed) so the 5th didn’t dissolve like the others because the tea was hot or warm enough anymore it cooled down. So the sugar won’t dissolve no more.
That's a ionic compound because it has a metal and polyatomic parts within the chemical formula.
THe balanced chemical reaction would be:
Na2CO3 + H2SO4 = Na2SO4 + H2O + CO2
We first convert the mass of sulfuric acid solution to moles by the molar mass. Then, we relate H2SO4 with Na2CO3 from the reaction. We do as follows:
<span>6.05×10^3 kg H2SO4 ( 1 kmol / 98.08 kg) ( 1 kmol Na2CO3 / 1 kmol H2SO4 ) ( 105.99 kg / kmol ) = 6537.92 kg Na2CO3 needed</span>