2naoh + h2so4 → na2so4 + h2o the equation is because the number of hydrogen atoms and in the reactants and in the products. for the first one : unbalanced or balanced second one : oxygen or soduim last one: equal or not equal

Two solutions of the same uv-absorbing molecule were analyzed by uv-vis spectroscopy on the same instrument using 1 cm pathlength cells. use data from the table to calculate by what percentage the concentration of solution b is compared to that of solution a.sample absorbance at 315nm a 0.45 b 0.80