Ben and Jerry were testing powders in science lab. First they put the powder in a zip lock bag. Next they added some water. The
powder fizzed and bubbled; soon it disappeared. When the bubbling stopped the bag contained a clear liquid and a lot of gas. What is the MOST OBVIOUS sign of a chemical change in this reaction. A) A gas was produced. B) The powder mixed with the water. C) There was a change in temperature. D) The powder dissolved in the water.
In a chemical change there is always a change in the chemical composition. When reactant reacts with one another new products are formed, the products have a different chemical composition than the reactants. Option A is correct as gases have evolved as a result of chemical change.
Option B and D are physical changes therefore incorrect. When matter dissolves in water or mixes with another substance there is no change in the chemical composition of the said matter.
Option C is incorrect as change in temperature is a change in the kinetic energy of matter and is not a chemical change.
As can be seen, in the overall reaction we have in the reactants like in the second reaction and in the products. The is in the first reaction but as a reactant so we need to reverse that reaction:
Answer: We do not know. We have not been given the solubility of oxygen in water at a given temperature nor have we been given the Henry's laws constant. We also do not know whether you mean 1 atmosphere of air, or 1 atmosphere of oxygen.