Chemistry Flashcards
6 cards from real EIT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Chemistry flashcards as text
What is the molarity of a solution prepared by dissolving 40 g of NaOH (MW = 40 g/mol) in 1 liter of water?
Answer: 1.0 M
Molarity = moles/volume = (40 g ÷ 40 g/mol) / 1 L = 1.0 M.
What is the pH of a 0.01 M HCl solution?
Answer: 2
pH = −log[H⁺] = −log(0.01) = 2.
Which of the following is an example of an exothermic reaction?
Answer: Combustion of methane
Combustion of methane releases heat to the surroundings, making it exothermic.
The ideal gas law is PV = nRT. What are the SI units of the universal gas constant R?
Answer: J/(mol·K)
R = 8.314 J/(mol·K) in SI units, relating energy to amount of substance and temperature.
For a first-order reaction with rate constant k = 0.693 min⁻¹, what is the half-life?
Answer: 1.0 min
t½ = ln(2)/k = 0.693/0.693 = 1.0 min for a first-order reaction.
How many moles of O₂ are required to completely combust 2 moles of CH₄?
Answer: 4
The balanced equation CH₄ + 2O₂ → CO₂ + 2H₂O requires 4 moles of O₂ for 2 moles of CH₄.