JAMB - Chemistry (2003 - No. 19)

When 10g of sodium hydroxide is dissolved in 1000cm\(^3\) of water, the sodium formed is approximately
[Na = 23, H = 1, O = 16]

0.01 mol dm^-3

0.10 mol dm^-3

0.25 mol dm^-3

0.50 mol dm^-3

Note that Number of moles = \(\frac{mass}{Molar mass}\)

n = \(\frac{10}{40}\) = 0.25 mol.

⇒ 0.25 mol of Sodium hydroxide is dissolved in 1000cm\(^3\) = 1 dm\(^3\)

i.e 0.25mol dm\(^3\)