Step 1: Complete Question 1 ...no effect on litmus paper. This is because ammonia does not ionize in methylbenzene to produce hydroxide ions ($OH^-$), which are responsible for basic properties. Step 2: Answer Question 2 a) Calculate the number of moles of $H_2SO_4$. Volume of $H_2SO_4 = 25.0 \text{ cm}^3 = 0.0250 \text{ dm}^3$. Concentration of $H_2SO_4 = 0.100 \text{ mol dm}^{-3}$. $$ \text{Moles of } H_2SO_4 = \text{Concentration} \times \text{Volume} $$ $$ \text{Moles of } H_2SO_4 = 0.100 \text{ mol dm}^{-3} \times 0.0250 \text{ dm}^3 $$ $$ \text{Moles of } H_2SO_4 = \boxed{\text{0.00250 mol}} $$ b) Calculate the number of moles of $NaOH$ that reacted. The balanced chemical equation is: $$ H_2SO_4(aq) + 2NaOH(aq) \to Na_2SO_4(aq) + 2H_2O(l) $$ From the equation, $1 \text{ mole of } H_2SO_4$ reacts with $2 \text{ moles of } NaOH$. $$ \text{Moles of } NaOH = 2 \times \text{Moles of } H_2SO_4 $$ $$ \text{Moles of } NaOH = 2 \times 0.00250 \text{ mol} $$ $$ \text{Moles of } NaOH = \boxed{\text{0.00500 mol}} $$ c) Calculate the concentration of the $NaOH$ solution. Volume of $NaOH = 20.0 \text{ cm}^3 = 0.0200 \text{ dm}^3$. $$ \text{Concentration of } NaOH = \frac{\text{Moles of } NaOH}{\text{Volume of } NaOH} $$ $$ \text{Concentration of } NaOH = \frac{0.00500 \text{ mol}}{0.0200 \text{ dm}^3} $$ $$ \text{Concentration of } NaOH = \boxed{\text{0.250 mol dm}^{-3}} $$ Step 3: Answer Question 3 a) The type of reaction that occurs when $H_2SO_4$ reacts with $NaOH$ is a neutralization reaction. b) A common indicator used in this titration (strong acid-strong base) is phenolphthalein. Step 4: Answer Question 4 a) If phenolphthalein is used, the colour of the indicator in the conical flask (containing $H_2SO_4$) at the start of the titration is colorless. b) If phenolphthalein is used, the colour of the indicator in the conical flask at the end-point of the titration is pink. Step 5: Answer Question 5 a) Apparatus A is a burette. b) Apparatus B is a pipette. c) Apparatus C is a conical flask (or Erlenmeyer flask). d) Apparatus D is a retort stand (with a clamp). That's 2 down. 3 left today — send the next one.