Question

What is the evidence of a chemical reaction when solid calcium sulfite is added to hydrochloric acid?
A. Calcium chloride precipitates
B. the solution turns blue
C. bubbles of sulfur dioxide gas is produced
D. the pH decreases
E. hydrogen gas is released which makes a noise when lit on fire

Answer 1

Please if you could answer the question, add an explanation of why the answer is correct.

Answer 2

This is a double replacement reaction. These reactions usually form compounds in this manner:

AB + CD \(\to\) AD + BC

Element A combines with element D, and same with element C combining with element B.

In our case: A = \(\sf Ca^{2+}\)
B = \(\sf SO_3^{2-}\)
C = \(\sf H^+\)
D = \(\sf Cl^-\)

Our balanced equation following the DR format:
\[\sf CaSO_3 (s) + 2HCl (aq) \to CaCl_2(aq) +\color{red}{ SO_2 (g)} +H_2O(l)\]
A chemical reaction is understood when:\[\bullet ~~\sf \text{change of color of products formed}\]\[\bullet ~~ \sf \text{cloudiness}\]\[\bullet~~ \text{bubbles form}\]\[\bullet ~~\text{mixture gets warmer, colder, or emits light}\]

Answer 3

This is a double replacement reaction. Now, a double replacement occurs if the products are either solid of gas. In this case CaS2 and HCl produces H2S which escapes the system and that is the driving force of this reaction. Use this calculator : http://calistry.org/calculate/doubleReplacement !!

Answer 4

DR occurs if the products are either solid or gas or water

Answer 5

Did out explanations make any sense to you, @xBeEnchantedx ?

Answer 6

I understand what's being explained but could someone explain why H2O is formed from the equation? And what would be the answer to the question? I'm not sure how to tell from the reaction what chemical reaction occurs.