Activation energy is highest at:

George has 2 moles of water (H2O). He wants to calculate the number of water molecules. How many molecules does he have?

David is studying an ionic compound, NaCl. He wants to calculate the formula mass. He knows Na=23 and Cl=35.5. What is the formula mass of NaCl?

Xia is studying the concept of activation energy. She knows that an increase in temperature increases the rate of reaction. What happens to the activation energy when temperature is increased?

Chloe is studying the system and surroundings. She knows that in an exothermic reaction, heat flows from the system to the surroundings. What is the sign of q (heat) for the system?

Fatima is studying covalent bonds. She learns that covalent bonds involve the sharing of electrons. Which of the following is an example of a molecule with a single covalent bond?

Xia is studying corrosion and its prevention. She learns that corrosion can be prevented by making the metal the cathode. What is this method called?

Which step is necessary before stoichiometric calculations?

George is calculating the number of moles in 44 g of CO2. The molar mass of CO2 is 44 g/mol. How many moles?

Which reaction shows reduction?

Nadia is contrasting ionic and covalent compounds. She learns that covalent compounds are usually poor conductors of electricity. Why are covalent compounds poor conductors?

Which bond results in formation of ions?

Bilal is studying the energy changes in a reaction. He knows that the activation energy is the minimum energy required to start a reaction. How does increasing the temperature affect the reaction rate?

Uma is calculating the gram atomic mass of sodium. She knows that the atomic mass of Na is 23 amu. What is the gram atomic mass of sodium?

The main purpose of electroplating is to:

David is studying redox reactions in terms of transfer of oxygen. He learns that oxidation involves gain of oxygen while reduction involves loss of oxygen. In the reaction: 2Mg + O2 → 2MgO, which substance is reduced?

Molecular formula shows:

Sam is studying the effect of temperature on reaction rate. He knows that increasing temperature increases the rate of reaction. Why does this happen?

Structural formula shows:

Bilal is writing the molecular formula for glucose. He knows that the empirical formula is CH2O and the molar mass is 180 g/mol. What is the molecular formula?

Chloe is learning about chemical bonds. She understands that bonds form when atoms gain, lose, or share electrons. Which type of bond is formed when electrons are transferred from one atom to another?

Chloe is studying redox reactions in terms of transfer of hydrogen. She learns that oxidation involves loss of hydrogen while reduction involves gain of hydrogen. In the reaction: H2S + Cl2 → 2HCl + S, which substance is oxidized?

The property of solubility in water is common for:

Fatima is studying activation energy. She knows that a catalyst lowers the activation energy. What effect does this have on the rate of reaction?

Nora is studying the energy changes in respiration. She knows that glucose is oxidized to release energy. What is the final electron acceptor in aerobic respiration?

The anode in a galvanic cell is:

How many moles are present in 36 g of water?

Khalid is learning about galvanizing. He understands that galvanized steel is steel coated with zinc. How does zinc protect the steel?

Corrosion is an undesirable process because it:

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?