1 Julia is studying air quality indices. She understands that the AQI provides information about air quality. What does the AQI measure? A Only ozone levels B Concentrations of major air pollutants C Only particulate matter D Carbon dioxide levels
4 Julia is learning about phosphates in water. She knows that phosphates from fertilizers and detergents can enter water bodies. What is a disadvantage of phosphates in water? A They increase oxygen levels B They cause excessive algae growth (eutrophication) C They kill all harmful bacteria D They make water crystal clear
5 Khalid is comparing two sets of data from an experiment. He wants to know the spread of the data. Which statistical measure should he use? A Mean B Median C Mode D Range
6 Julia is conducting an experiment and wants to ensure that her data is valid. What does validity in experimental data refer to? A How close the data is to the true value B The consistency of the data C Whether the data measures what it is supposed to measure D The amount of data collected
8 David is studying the Bronsted-Lowry concept. In the reaction: NH3 + H2O → NH4+ + OH-, what is the base? A NH3 B H2O C NH4+ D OH-
9 Which type of graph is best for showing proportions? A Line graph B Bar graph C Pie chart D Scatter plot
10 Which acid reacts with metals to produce hydrogen gas? A Weak acids only B All acids C Strong acids D Dilute acids
11 Ming is studying the disadvantages of natural substances in water. He knows that some substances can affect water quality. Which of the following is a disadvantage of phosphates in water? A They increase fish population B They cause eutrophication C They make water safe to drink D They improve water clarity
12 Ozone layer depletion increases: A Visible light reaching Earth B Infrared radiation C Ultraviolet radiation D Humidity
14 Which of the following is NOT a type of chromatography studied here? A Paper chromatography B Thin-layer chromatography C Gas chromatography D None of these
15 Yusuf is studying the halogenation of alkanes. He knows that iodine does not react readily with alkanes. Why is iodine less reactive in halogenation? A Because the I-I bond is too strong B Because the reaction is endothermic C Because iodine is a solid at room temperature D Because iodine is more reactive than chlorine
16 Which solution is used to test acidic or basic gases? A Limewater B Litmus solution C Silver nitrate D Barium chloride
18 What is qualitative analysis mainly concerned with? A Amount of substance B Nature of substance C Mass of substance D Volume of substance
21 Hina is studying the classification of organic compounds. She learns that compounds can be classified as acyclic or cyclic. Which of the following is a cyclic compound? A Butane B Cyclopentane C Pentane D Hexane
22 What does a single spot on chromatogram indicate? A Mixture B Impure substance C Pure substance D Solvent only
23 Nadia is studying closed chain compounds. She learns that closed chain compounds contain rings. Which of the following is a closed chain compound? A Propane B Cyclobutane C Butane D Pentane
24 Rachel is studying the strength of bases. She knows that weak bases partially ionize in water. Which of the following is a weak base? A NaOH B KOH C NH3 D Ca(OH)2