Ms. Pitt set up a classroom demonstration to show what happens when a sample of zinc metal is add a. ed to a flask containing hydrochloric acid (HCl). The diagram shows what the students in the classroom observed during the demonstration. The students made two other observations: The flask felt warmer after adding the sample. The sample became smaller over time. Which of the following is NOT an evidence of a chemical reaction in this example. A. Gas collected in the balloon
B. Temperature of sample is increased
c. Volume of HCl remains the same
D. Size of the zinc has become smaller

volume of HCl remains the same

Reaction

Zn (s) + 2HCl (aq)  ⇒  ZnCl₂ (s) + H₂ (g)

A. gas H₂ collected: true

B. Every chemical reaction produces or absorbs heat. In chemistry, this effect is described as the enthalpy of a reaction.

This reaction releases heat (exothermic) and causes the temperature to increase: true

C. the volume of HCl will decrease because it reacts: false

D. the size of the zinc metal decreases as it reacts: true

answer: the primary difference between a hypothesis and a theory is that b hypothesis is falsifiable, but a theory has been proven to be correct. theory is an explanation of something that is happening but hypothesis is a guess of something that can happen

explanation: