In the reaction Na2CO3 + 2HCl → 2NaCl + CO2 + H2O, how many grams of CO2 are produced when 7.5 moles of HCl is fully reacted?

165 of CO₂.

Explanation:

In the reaction:

Na2CO3 + 2HCl → 2NaCl + CO2 + H2O

2 moles of HCl reacts producing 1 mole o CO₂

If 7.5 moles of HCl reacts, moles of CO₂ produced are:

7.5 moles of HCl ₓ ( 1 mol CO₂ / 2 mol HCl) = 3.75 mol CO₂. As molar mass of CO₂ is 44g/mol, mass of CO₂ is:

3.75 mol CO₂ ₓ (44g / 1mol) = 165 of CO₂

Explanation:

Equation of the reaction

Na2CO3 + 2HCl → 2NaCl + CO2 + H2O

Given:

Number of moles of HCl, nA = 7.5 moles

By stoichiometry, 2 moles of HCl reacted fully to liberate 1 mole of CO2 gas.

Therefore, number of moles of CO2, ng = 7.5/2 × 1 moles

= 3.75 moles

Mass = molar mass × number of moles

Molar mass of CO2 = 12 + (16 × 2)

= 44 g/mol

Mass of CO2 = 44 × 3.75

= 165 g of CO2

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e