How do the products and reactants of a chemical change compare?

the mass of the products is greater than the mass of the reactants because energy is absorbed by the reaction.

the mass of the products equals the mass of the reactants because energy is not absorbed or given off by the reaction.

the mass of the products is less than the mass of the reactants because energy is given off by the reaction.

the mass of the products equals the mass of the reactants because the same atoms are present throughout the reaction

Use the table to identify the phase and phase changes of the elements under the given conditions. write the name of the substance, phase, or phase change

Calculate the ratio of h+ ions to oh– ions at a ph = 7. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 7. are they the same? why or why not? record your comparison in table a. what is the concentration of h+ ions at a ph = 7? mol/l what is the concentration of oh– ions at a ph = 7? mol/l what is the ratio of h+ ions to oh– ions at a ph = 7? : 1

Aconcentrated solution of ammonia is 14.8m and has a density of 0.899g/l. what is the concentration of ammonia in this solution in weight percent (%w/w)?