Rusty in Stoichiometry

Was given this question in a forum I was active in….I stared at it rummaging in the far corner of my brain knowing it was a relatively simple question… I have a nagging feeling this won’t be the only time this year.

This really showed how rusty I am in my subjects… Although I did manage to solve it with some help from my old (and dusty) notes…

For those curious here’s the question…

• 6.956g of hydrated sodium carbonate Na2CO3.xH2O were dissolved in water and made up to exactly 250 cm3.
• 25 cm3 of this solution was neutralized by 48.80cm3 of 0.05mol/dm3 of Sulphuric Acid.
• Calculate the value of x in the formula.

(p.s. the answer is 10).