Answer:
2NaOH + CO2 -> Na2CO3 + H2O
1) Find the moles of each substance

2) Determine the limitting reagent

∴ Carbon dioxide is limitting as it has a smaller value.
3) multiply the limiting reagent by the mole ratio of unknown over known
n(H2O ) = 0.3976369007 × 1/2
= 0.1988184504 moles
4) Multiply the number of moles by the molar mass of the substance.
m = 0.1988184504 × (1.008 × 2 + 16.00)
= 0.1988184504 × 18.016
= 3.581913202 g
Explanation:
B is the right answer because it’s a double replacement reaction and the potassium is balanced with the sulphate
We know that
pH = -log[H+]
the pH value falls in between 0- 7 for acids
As the pH value increases the concentration of [H+] increases.
similarly as the value of pH approaches 0, the concentration of H+ increases
The solution said to become more acidic
Also
[H+] X [OH-] = 10^-14
Thus pH + pOH = 14
hence the concentration of OH- decreases as the pH approaches zero