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Questions in chemistry

[Done] Why do the two elements, silver and iron, have different properties?

[Done] What chemical compound is [tex]C_2H_5OH[/tex]?

[Done] The chain on a bicycle rusts faster when the bicycle is left outside in damp conditions. Which of the following factors affect the rate at which the bicycle chain rusts? A. Surface area B. Concentration of oxygen atoms in air C. Temperature D. All of the above E. B and C F. A and C G. A and B

[Done] Alexis was interested in the way mirrors reflect. The living room of Alexis' house had one big window in the front, and a very large mirror on the back wall. Alexis hypothesized that the room would heat up faster in the morning with the mirror on the wall than it would if the mirror were covered with a sheet that was the same color as the walls. What will make Alexis' hypothesis valuable? A. It cannot be valuable because the investigation is in her house and not in the science lab. B. Any testable hypothesis is valuable. C. It will be valuable only if it is proved incorrect. D. It will be valuable only if it is proved correct.

[Done] Enzymes increase the rate of a reaction by __________? A. Contributing water to the reaction. B. Contributing electrons to the reaction. C. Changing the pH of the substrates. D. Decreasing activation energy. E. Increasing the temperature of the substrates.

[Done] A solution tested in the laboratory shows a pH of 14. Which of the following statements best describes this solution? A. It is a highly acidic solution with a high hydrogen ion concentration. B. It is a highly alkaline solution with a high hydrogen ion concentration. C. It is a highly basic solution with a high hydrogen ion concentration.

[Done] Which of these sentences is true about nitrogen? A. As nitrogen is the rarest gas in the atmosphere, very few organisms can use it directly. B. Even though nitrogen is an abundant gas in the atmosphere, very few organisms can use it directly. C. Even though nitrogen is an abundant gas in the atmosphere, no organisms can use it directly.

[Done] What is the pH of a solution with a concentration of [tex]2.4 \times 10^{-5}[/tex] molar [tex]H_3O^+[/tex]? Please show or explain the work used to solve this problem.

[Done] How much energy is released when 2.65 kg of diethyl ether \((\text{C}_2\text{H}_5)_2\text{O}\) freezes? The heat of fusion for diethyl ether is 7.27 kJ/mol.

[Done] A chemical system at equilibrium is referred to as dynamic because the: A) rates of the forward and reverse reactions continue changing B) forward and reverse reactions continue reacting C) value of the equilibrium constant (K) changes D) concentrations of the components continue changing