1.2 Synthesising scientific method

A hypothesis is

• a smart guess

• a tentative explanation to a phenomenon

• the conclusion of an experiment

• sometimes incorrect

What is the first step in scientific method?

• Making hypothesis

• Making observation

• Making inference

• Collecting data

The scientific method involves the following variables, except

• chemical variable

• fixed variable

• manipulated variable

• responding variable

How can we decide whether our hypothesis for a scientific investigation is true or not?

• After we have written the report

• After we have changed the variables of the investigation

• After we have planned how to test the hypothesis

• After we have interpreted the data collected

Which of the following statements is true?

• All senses must be used during observation

• Data should be changed whenever necessary.

• One measurement is enough to ensure accuracy.

• Interpretation of data should be done objectively.

A chemist can present his/her experiment results

• graph

• picture

• calculation

• table

• A

• B

• C

• D

A student is required to study the effect of a quantity of manganese(IV) oxide on the rate of decomposition of hydrogen peroxide to water and oxygen according to the equation: 2H₂O₂ 2H₂O + O₂

The responding variable for the experiment is

• the rate of release of oxygen gas

• the rate of increase in concentration of hydrogen peroxide

• the rate of increase in temperature of hydrogen peroxide

• the rate of decrease in mass of manganese(IV) oxide

• The melting point of ice is different.

• The freezing point of ice is influenced by the mass of sodium chloride added

• The more sodium chloride is added to the ice, the lower the freezing point is.

• There is a relationship between the mass of sodium chloride added and the freezing point of ice.

• A

• B

• C

• D