500mL de uma solução 0,2 mol. L-1 de NaCl são misturadas com 200mL de uma solução 0,6 mol. L-1 de KCl. As concentrações, em mol/L, da solução resultante em relação aos íons Na+, K+ e Cl- são respectivamente: A) 0,125; 0,136; e 0,260
B) 0,301; 0,142; e 0,443
C) 0,142; 0,171; e 0,313
D) 0,201; 0,163; e 0,364

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)

Suppose you mix one mole of sulfuric acid (h2so4) with 1 mole of sodium hydroxide(naoh). why does the ph of the solution remain below 7? ( explain so i can get better understanding! )