The oxidation state of an element in its free state is:

Bilal is learning about reduction in terms of gain of electrons. He understands that reduction involves the gain of electrons. Which of the following represents reduction?

Which statement best describes a redox reaction?

Which substance is necessary for rusting of iron?

Ahmed is studying oxidation and reduction in his chemistry class. His teacher explains that oxidation is the loss of electrons. Based on this definition, which of the following processes represents oxidation?

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+?

Which battery is rechargeable?

Which method prevents corrosion by coating iron with zinc?

An oxidizing agent is a substance that:

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+?

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?

Electroplating is used to:

Which of the following is NOT a method to prevent corrosion?

Oxidation number of oxygen in most compounds is:

George is studying oxidation states of monoatomic ions. He knows that a monoatomic ion's oxidation state is its charge. What is the oxidation state of Ca2+?

Waleed is learning about oxidation and reduction in terms of electron transfer. He knows that a substance that loses electrons is oxidized. In the reaction: Fe + CuSO4 → FeSO4 + Cu, which substance loses electrons?

A voltaic cell is also known as:

Julia is determining the oxidation number of an atom in a compound. She wants to find the oxidation state of sulfur in H2SO4. Given that H is +1 and O is -2, what is the oxidation state of S?

Nadia is studying the formula of ionic compounds. She knows that the formula must be neutral. What is the formula of the ionic compound formed between magnesium (Mg2+) and chloride (Cl-)?

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?

Which component maintains electrical neutrality in a voltaic cell?

Mohamed is learning about prevention of corrosion. He understands that painting is a common method to prevent corrosion. How does painting prevent corrosion?

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?

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?

Laura is studying the prevention of corrosion. She learns that painting is a common method. Which of the following is an advantage of using paint for corrosion prevention?

Qasim is learning about electroplating. He understands that electroplating is a process that uses an electric current to coat a metal with another metal. Which of the following is a common application of electroplating?

Rania is studying cathodic protection. She learns that cathodic protection involves making the metal the cathode to prevent corrosion. Which of the following uses cathodic protection?

A dry cell is commonly used in:

Samir is learning about the formula of ionic compounds. He knows that the formula must be electrically neutral. What is the formula of the ionic compound formed between sodium (Na+) and sulfate (SO4^2-)?

Ethan is studying cathodic protection. He learns that this method is often used to protect underground pipelines. What is the principle behind cathodic protection?