Use the given thermochemical expressions to calculate the Δr…

Use the given thermochemical expressions to calculate the ΔrH° for the last reaction. Thermochemical expressions Reaction ΔrH° (kJ) CH3OH(ℓ) + O2(g) → HCOOH(ℓ) + H2O(ℓ) -471.89 2HCOOH(ℓ) + O2(g) → 2CO2(g) + 2H2O(ℓ) -509.24 CH3OH(ℓ) → CH3OH(g) 38 CH3OH(g) + 3/2O2(g) → CO2(g) + 2H2O(ℓ) ?  

In Han Dynasty China, there is evidence of dissections of co…

In Han Dynasty China, there is evidence of dissections of corpses. This is in the form of organ measurements in the Inner Canon of the Yellow Emperor, and later accounts from physicians suggesting that some vivisection was practiced, exclusively during surgery, to investigate damage. These anatomical investigations however were neither comprehensive (only organs in the digestive tract are mentioned), nor frequent.

Consider a table consisting of data about dishes and the ing…

Consider a table consisting of data about dishes and the ingredients used to prepare them. Three attributes are present in this table: DishID, which is the ID for a dish; IngredientID, which is the ID for a specific ingredient; IngredientPrice, which is the price for the ingredient. The price of an ingredient is independent from the dishes the ingredient is used.   Consider the following two scenarios:  Scenario 1: Each dish has exactly one ingredient being used;  Scenario 2: Each dish has one or more than one ingredients used.   You may also assume that the relation table is already in 1NF, meaning that there are no multi-valued attributes and the primary key(s) are identified. This means that in scenario 1, the primary key is DishID and in scenario 2, the primary keys are DishID + IngredientID. Which of the following statement is true?