Question

Nitya took two test tubes A and B. In test tube
A she put 10 mL of dilute NaOH and in tes
tube B she put 10 mL of dilute HCI. Write the
changes observed in both the test tubes or
adding a pinch of sodium carbonate and also
write the chemical reaction involved.
Define pH scale
111
[2]
6 th question

Answer 1

There will be no observed change in first case while in second case brisk effervescence will be seen.

In test tube 1 -

Since, both the reactants contains Na+ or sodium ions, no visible reaction occurs.

In test tube B -

2HCl + Na2CO3 -> NaCl + H2O + CO2

HCl is hydrochloric acid, Na2CO3 is sodium carbonate, NaCl is salt, H2O is water and CO2 is Carbon dioxide gas released visibly as brisk effervescence.