Is this investigation a controlled experiment or an observational study? Explain your answer.

Enough of a monoprotic weak acid is dissolved in water to produce a 0.0172 m solution. if the ph of the resulting solution is 2.39 at 20 °c, determine the pka for the acid.

Which of the following signs of a chemical reaction are observed in the reaction of potassium with water? precipitate formed temperature change smell produced gas produced color change

Marcel just purchased 1.69 grams of iron fillings in order to make living putty for his 6 year old niece. how many moles of iron are made in his sample?