2 Usman is learning about the formula of ionic compounds. He knows that the formula is written by balancing the charges. What is the formula of the ionic compound formed between calcium (Ca2+) and phosphate (PO4^3-)? A CaPO4 B Ca3(PO4)2 C Ca2(PO4)3 D Ca(PO4)2
3 Yara is learning about the formula of ionic compounds. She knows that polyatomic ions can be included in the formula. What is the formula of the ionic compound formed between ammonium (NH4+) and carbonate (CO3^2-)? A NH4CO3 B (NH4)2CO3 C NH4(CO3)2 D -
4 Waleed is determining the oxidation number of an atom in a compound. He wants to find the oxidation state of chromium in K2Cr2O7. Given K is +1 and O is -2, what is the oxidation state of Cr? A +3 B +6 C +4 D +7
6 Khalid is learning about oxidizing and reducing agents. He understands that an oxidizing agent causes oxidation of another substance and is itself reduced. In the reaction: CuO + H2 → Cu + H2O, which is the oxidizing agent? A CuO B H2 C Cu D H2O
7 Nadia is studying alloying as a method of corrosion prevention. She learns that alloying involves mixing metals to improve properties. Which of the following is an alloy that is resistant to corrosion? A Steel B Stainless steel C Cast iron D Carbon steel
8 Hina is studying monoatomic ions. She learns that the oxidation state of a monoatomic ion is equal to its charge. What is the oxidation state of Na+? A 0 B +1 C -1 D +2
9 Zayn is learning about redox reactions. He understands that a redox reaction involves the transfer of electrons. Which of the following is a redox reaction involving transfer of electrons? A Na + Cl → NaCl B NaCl → Na+ + Cl- C Na+ + Cl- → NaCl D None of the above
10 Emma is learning about redox reactions in photography. She discovers that silver bromide (AgBr) is used in photographic films. In the photographic process, AgBr is reduced to Ag. What happens to AgBr in this process? A It is oxidized B It is reduced C It undergoes both oxidation and reduction D It does not react
11 The electrolyte in an electrochemical cell is: A A metal B A conductor of electrons C A solution that conducts ions D An insulator
12 Rania is learning about corrosion prevention methods. She learns that electroplating is used to coat a metal with a thin layer of another metal. Which of the following is an example of electroplating? A Coating iron with zinc B Coating steel with chromium C Coating copper with tin D Coating aluminum with paint
13 Tina is studying oxidation states of monoatomic ions. She knows that the oxidation state is equal to the ion's charge. What is the oxidation state of Al3+? A +1 B +2 C +3 D -3
14 Usman is learning about oxidation and reduction in terms of electron transfer. He knows that in a redox reaction, one substance is oxidized and another is reduced. In the reaction: 2Na + Cl2 → 2NaCl, which substance is oxidized? A Na B Cl2 C NaCl D Both Na and Cl2
15 Electrons flow in an external circuit from: A Cathode to anode B Anode to cathode C Electrolyte to electrode D Salt bridge to solution
16 Samir is studying the prevention of corrosion by coating with a thin layer of another metal. He learns that galvanizing is one such method. What metal is used in galvanizing to coat iron? A Tin B Chromium C Zinc D Nickel
17 A reducing agent is a substance that: A Gains electrons B Loses electrons C Accepts oxygen D Stops reduction
18 Electroplating is used to: A Remove rust B Protect metals and improve appearance C Increase corrosion D Purify metals
19 Khalid is learning about galvanizing. He understands that galvanized steel is steel coated with zinc. How does zinc protect the steel? A By forming a protective layer of zinc oxide B By acting as a barrier and as a sacrificial anode C By making the steel non-reactive D By changing the steel's structure
20 Ibrahim is studying polyatomic ions. He learns that the sum of oxidation states in a polyatomic ion is equal to the charge of the ion. In the sulfate ion (SO4^2-), what is the total sum of oxidation states? A 0 B +2 C -2 D +4
21 Xia is learning about oxidizing agents. She understands that an oxidizing agent is itself reduced. In the reaction: 2FeCl2 + Cl2 → 2FeCl3, which is the oxidizing agent? A FeCl2 B Cl2 C FeCl3 D Both A and B
22 Tina is learning about redox reactions in photography. She understands that the developer reduces silver halide to silver. What is the role of the developer in the photographic process? A It oxidizes the silver halide B It is a reducing agent C It is an oxidizing agent D It dissolves the silver halide
23 The cathode in a galvanic cell is: A Negatively charged B Neutral C Positively charged D Insulated
24 Mohamed is learning about corrosion. He understands that corrosion can be prevented by cathodic protection. Which of the following structures commonly uses cathodic protection? A Wooden fences B Underground pipelines C Plastic containers D Glass bottles
25 Fatima is studying oxidation states. She learns that oxidation state is the charge an atom would have if all bonds were ionic. What is the oxidation state of oxygen in most compounds? A 0 B +1 C -2 D +2