3 (a) An acid can be reacted with a base in a titration experiment - Edexcel - GCSE Chemistry - Question 3 - 2015 - Paper 1

The correct equation is option D: acid + base → salt + water.

To find the mass of solid sodium hydroxide transferred to the flask, use the formula:

$\text{mass of sodium hydroxide} = \text{mass of container + solid sodium hydroxide} - \text{mass of empty container}$

Substituting the values:

$\text{mass of sodium hydroxide} = 17.12 g - 7.02 g = 10.10 g$

To find the concentration, use the formula:

$\text{Concentration} = \frac{\text{mass of sodium hydroxide}}{\text{volume of solution}}$

Here, the volume of the solution is 2 dm³ and the mass of sodium hydroxide is 10.10 g:

$\text{Concentration} = \frac{10.10 g}{2 dm³} = 5.05 g \, dm^{-3}$