During a chemical reaction, what remains constant? composition, temperature, energy, the substance

100mg magnesium reacts with 20ml of 1.0m hcl

How many grams of co(g) are there in 74.5 ml of the gas at 0.933 atm and 30o c?

Which statement correctly identifies the scientific question and describes why the question is scientific? question 1 refers to the supernatural.question 2 reflects a moral or social value.question 3 refers to something that can be measured.question 4 reflects a question that can’t be observed.