### Question 1

**When plotting a graph to determine the relationship between two variables, which of the following is the most important factor to consider?**

A. Colour of the graph

B. Size of the graph paper

C. Proper scaling and labelling of axes

D. The brand of the pen used

### Question 2

**Which type of graph is most suitable for representing categorical data?**

A. Scatter plot

B. Line graph

C. Bar graph

D. Pie chart

### Question 3

**In the context of an experiment, what does the gradient of a graph typically represent?**

A. The initial value of the dependent variable

B. The change in the independent variable per unit change in the dependent variable

C. The total change in the dependent variable

D. The average value of the independent variable

### Question 4

**If a graph of volume (V) against temperature (T) for a gas gives a straight line with a negative y-intercept, what does the y-intercept represent?**

A. Absolute zero in Celsius

B. Absolute zero in Kelvin

C. Boiling point of the gas

D. Melting point of the gas

### Question 5

**Why is it important to include error bars in a graph?**

A. To make the graph look more professional

B. To indicate the precision of the data

C. To show the range of possible values for each data point

D. To indicate the accuracy of the data

### Question 6

**a)** Describe the importance of proper scaling and labelling of axes when plotting a graph in a chemistry experiment. [3]

**b)** Explain the difference between a scatter plot and a bar graph, and provide a scenario in a chemistry context where each would be most appropriate. [3]

### Question 7

**a)** Define the terms "gradient" and "y-intercept" in the context of a linear graph. [2]

**b)** How can the gradient and y-intercept of a graph be used to make predictions about an experiment? Provide an example. [3]

### Question 8

**a)** What is the significance of including units and error bars in a graph? [3]

**b)** Describe a scenario in a chemistry experiment where transforming non-linear data into a linear form would be beneficial. [2]

### Question 9

**a)** Explain the difference between systematic and random errors in the context of a chemistry experiment. [3]

**b)** How can systematic errors be identified and corrected? [3]

**c)** Describe a scenario where random errors might be more prevalent and suggest ways to minimise them. [3]

### Question 10

**a)** What is the importance of choosing the appropriate graph type in representing data from a chemistry experiment? [3]

**b)** Describe a situation where a bar graph would be more appropriate than a scatter plot. [2]

**c)** How does the interpretation of the gradient differ between a distance-time graph and a concentration-time graph in a reaction experiment? [3]

### Question 11

**When data on a graph does not form a straight line, which technique can be used to linearise the data?**

A. Multiplying all values by 2

B. Taking the logarithm of the data

C. Adding a constant to all values

D. Squaring all values

### Question 12

**Which of the following is NOT a common method for transforming non-linear data into a linear form?**

A. Taking the square root

B. Taking the inverse

C. Doubling the values

D. Taking the logarithm

### Question 13

**In the context of an experiment, what does the y-intercept of a graph typically represent?**

A. The initial value of the dependent variable when the independent variable is zero

B. The maximum value of the dependent variable

C. The average value of the independent variable

D. The final value of the dependent variable

### Question 14

**Which of the following is NOT a reason for transforming non-linear data into a linear form?**

A. To make the graph look more appealing

B. To determine relationships between variables

C. To simplify the analysis of the data

D. To make predictions based on the linear relationship

### Question 15

**If the gradient of a graph represents speed and the y-intercept represents the initial distance from a reference point, what does a positive y-intercept indicate?**

A. The object started from behind the reference point

B. The object started at the reference point

C. The object started ahead of the reference point

D. The object's speed was zero at the start

### Question 16

**a) **Why is it essential to include error bars in a graph, especially in a chemistry context? [2]

**b) **Explain the difference between absolute and relative uncertainty. [3]

**c) **How can the propagation of uncertainty affect the final result in a multi-step calculation? Provide an example. [4]

### Question 17

**a)** What does the y-intercept represent in a graph plotting concentration against time for a reaction? [3]

**b)** How can non-linear data be transformed into a linear form? Provide two common methods. [3]

**c)** Why is it important to transform non-linear data into a linear form in certain experiments? [3]

### Question 18

**a)** Describe the difference between accuracy and precision in the context of chemical measurements. [3]

**b)** If a student repeatedly measures the mass of a substance and obtains values of 10.2g, 10.3g, and 10.1g, is the student's method accurate, precise, or both? Justify your answer. [3]

**c) **Explain the significance of the gradient in a graph that plots the volume of gas produced against time during a reaction. [3]

**d)** How can the gradient of such a graph be used to make predictions about the reaction's future progress? [3]

### Question 19

**a)** Why is proper scaling of axes crucial in a chemistry graph? [2]

**b)** Describe a situation where a scatter plot would be more appropriate than a bar graph in representing chemical data. [3]

**c)** How can the y-intercept of a graph be used to determine initial conditions in a chemical experiment? [3]

**d)** Explain the importance of including units in a graph, especially in a chemistry context. [4]

### Question 20

**a)** What are the primary sources of uncertainty in chemical measurements? [3]

**b)** Differentiate between absolute and relative uncertainty and provide an example of each. [3]

**c)** How can error bars on a graph help in understanding the reliability of data points? [3]

**d) **Describe a method to calculate the propagation of uncertainty when multiplying two measured values. [4]