A 679-mL sample of unknown HCl solution reacts completely with Na2CO3 to form 11.1 g CO2. What was the concentration of the HCl solution?

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

What must be in balance for temperatures to remain constant?

What is a substance? a. a physical property of matter b. a chemical property of matter c. an element or compound that cannot be physically separated d. characteristics used to tell the difference between mixtures