Be sure that all of the copper has reacted, but try not to use too much excess acid. Why? Add the sodium hydroxide with a dropper until no more precipitate forms, then use a hot plate to heat the contents of the beaker. A stirring rod will help you see when all the precipitate has undergone a change. Gravity filtration should be sufficient to separate the solid from the liquid. Rinse the ppt well. Why? Allow to dry and remass.
How many kilograms of sodium bicarbonate could be formed from a metric ton of the sodium sulfate, assuming an 85% yield in each step?