Find the % by mass of oxygen if a compound is decomposed by an electric current giving 19.98 g O and 2.52 g H.

Consider three unlabeled bottles, each contain small pieces of one of the following metals. - magnesium - sodium - silver the following reagents are used for identifying the metals. - pure water - a solution of 1.0 molar hcl - a solution of concentrated hno3 (a) which metal can be easily identified because it is much softer than the other two? describe a chemical test that distinguishes this metal from the other two, using only one of the reagents above. write a balanced chemical equation for the reaction that occurs. (b) one of the other two metals reacts readily with the hcl solution. identify the metal and write the balanced chemical equation for the reaction that occurs when this metal is added to the hcl solution. use the table of standard reduction potentials (attached) to account for the fact that this metal reacts with hcl while the other does not. (c) the one remaining metal reacts with the concentrated hno3 solution. write a balanced chemical equation for the reaction that occurs. (d) the solution obtained in (c) is diluted and a few drops of 1 m hcl is added. describe what would be observed. write a balanced chemical equation for the reaction that occurs.

24 points and brainliest to anyone who can answer under 10 minutes with best ! the table below shows the role of different substances during photosynthesis. substance role during photosynthesis glucose stores chemical energy water combines with glucose to form carbon dioxide chlorophyll traps sunlight which of the following statements would correct one of the roles listed in the table? glucose combines with carbon to form water. chlorophyll reacts with light to produce carbon dioxide. water combines with carbon dioxide during photosynthesis. chlorophyll stores chemical energy needed for photosynthesis.

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.