Using concentrations of solutions in mol/dm3 (chemistry only) (HT only): แบบฝึกหัด

In a titration, \(25.0\text{ cm}^3\) of \(0.100\text{ mol/dm}^3\) sodium hydroxide (\(\text{NaOH}\)) is neutralised by exactly \(20.0\text{ cm}^3\) of sulfuric acid (\(\text{H}_2\text{SO}_4\)).
The equation for the reaction is:
\(2\text{NaOH} + \text{H}_2\text{SO}_4 \rightarrow \text{Na}_2\text{SO}_4 + 2\text{H}_2\text{O}\)
Calculate the concentration of the sulfuric acid.

What mass of anhydrous sodium carbonate, \(\text{Na}_2\text{CO}_3\), is required to prepare \(500\text{ cm}^3\) of a solution with a concentration of \(0.2\text{ mol/dm}^3\)?
(Relative formula mass: \(\text{Na}_2\text{CO}_3 = 106\))

A solution of sodium chloride has a concentration of 0.200 mol/dm³. Calculate the mass of \(NaCl\) dissolved in 250 cm³ of this solution.
(Relative atomic masses: \(Na = 23\), \(Cl = 35.5\))

In a titration, 20.0 cm³ of 0.500 mol/dm³ hydrochloric acid (\(HCl\)) neutralises 25.0 cm³ of sodium hydroxide (\(NaOH\)) solution. Calculate the concentration of the \(NaOH\) solution in g/dm³.
\(NaOH + HCl \rightarrow NaCl + H_{2}O\)
(Relative atomic masses: \(Na = 23, O = 16, H = 1\))

A chemist prepares a solution by dissolving \(4.00\text{ g}\) of sodium hydroxide (\(NaOH\)) to make a final volume of \(500\text{ cm}^{3}\). Calculate the concentration of the solution in \(mol/dm^{3}\).
(Relative atomic masses: \(Na = 23\), \(O = 16\), \(H = 1\))

A solution of sulfuric acid (\(H_2SO_4\)) has a concentration of \(0.250 \text{ mol/dm}^3\).

(a) Calculate the mass of sulfuric acid dissolved in \(200 \text{ cm}^3\) of this solution. (2 points)

(b) Convert the concentration of the solution from \(mol/dm^3\) to \(g/dm^3\). (2 points)

(Relative atomic masses: \(H = 1, S = 32, O = 16\))

In a titration, \(25.0 \text{ cm}^3\) of \(0.150 \text{ mol/dm}^3\) sodium hydroxide solution (\(NaOH\)) was neutralised by \(30.0 \text{ cm}^3\) of hydrochloric acid (\(HCl\)).

The equation for the reaction is:
\(NaOH(aq) + HCl(aq) \rightarrow NaCl(aq) + H_2O(l)\)

(a) Calculate the number of moles of \(NaOH\) used in the titration. (1 point)

(b) Determine the concentration of the hydrochloric acid in both \(mol/dm^3\) and \(g/dm^3\). (4 points)

(Relative atomic masses: \(H = 1, Cl = 35.5\))