CSEC Chemistry Paper 2 January 2021 - Free CXC Past Paper with Answers

Using the thermometer readings in Figure 1, on page 5, complete Table 1 by recording the temperatures for the additions of $5 \text{ cm}^3$, $15 \text{ cm}^3$ and $25 \text{ cm}^3$ of $H_2SO_4$.

TABLE 1: EXPERIMENTAL RESULTS

Using the axes provided in Figure 2, on page 7, plot the graph of temperature against volume of acid added.

Using the axes provided in Figure 2, on page 7, plot the graph of temperature against volume of acid added.

Draw two lines of best fit through the points on the graph, one where the temperature is increasing and the other where the temperature is decreasing.

On your graph, show the end point of the reaction. Record the corresponding volume below.

End point of the reaction = 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End point of the reaction = $\text{20 cm}^3$

Distinguish between a 'strong acid' and a 'weak acid'.

Write a balanced chemical equation for the reaction between $\text{NaOH}$ and $\text{H}_2\text{SO}_4$.

Calculate the number of moles of $\text{H}_2\text{SO}_4$ used in the reaction.

Calculate the number of moles of $\text{NaOH}$ in $25 \text{ cm}^3$ of the solution.

Calculate the concentration of $\text{NaOH}$, in $\text{mol dm}^{-3}$.

Calculate the concentration of $\text{NaOH}$, in $\text{gdm}^{-3}$, given the molar mass of $\text{NaOH} = 40 \text{ gmol}^{-1}$.

State whether the reaction that took place in the styrofoam cup was exothermic or endothermic. Explain your answer.

State ONE safety precaution which should have been taken during the experiment.