1 When 0.25 g of sodium metal was added to 200cm3 (an excess)
water, the following reaction occurred.
Na +H2O → NaOH +1/2 H2
(a)Calculate the number of moles of sodium taking part in the reaction.
(b) Calculate the concentration in moldm-3 of the sodium hydroxide
which was formed.
( c) Calculate the volume of hydrogen formed at 300k.Assume that
hydrogen is insoluble in water at 300k (assume one mole of gas
occupies 24dm3 at 300k)
2 By titration, you find that 15.00cm3 of hydrochloric acid neutralize
25.00cm3 of a 0.100mol dm-3 solution of sodium hydroxide.
What is the concentration of hydrochloric acid.
3 25.00cm3 of sulphuric acid of concentration 0.1500mol dm-3 acid
neutralized 31.2cm3 of potassium hydroxide solution.
Find the concentration of the potassium hydroxide solution.
4 A solution of sodium hydroxide contains 10gdm-3.
(a) What is the concentration of the solution in mol dm-3.
(b) What volume of this solution would be needed to neutralize
25.0cm3 of 0.10moldm-3 hydrochloric acid.
5 Sodium carbonate crystals 27.823g were dissolved in water and
made up to 1.00dm3.25cm3 of the solution were neutralized by
48.8 cm3 of hydrochloric acid of concentration 0.100mol dm-3.
Find n in the formula of Na2CO3 n H2O
PPm
1kg of a solution contains 0.100 mol of calcium ions,Ca2+ .What is the
concentration of the Ca2+ ions by mass in ppm?