What does Hess's law state can be done in order to be able to react solid magnesium with oxygen gas safely (that is, without exp
osing the magnesium to flames)?A. More moles of solid magnesium can be added until the reaction is safe.B. More moles of oxygen gas can be added until the reaction is safe.C. The reaction can be broken down and performed in steps. D. The phase state of the reactants can be changed to match each other.E. The phase state of the products can be changed to match each other.
C. The reaction can be broken down and performed in steps
Explanation:
Hess's Law of Constant Heat Summation states that irrespective of the number of steps followed in a reaction, the total enthalpy change for the reaction is the sum of all enthalpy changes corresponding to all the steps in the overall reaction. The implication of this law is that the change of enthalpy in a chemical reaction is independent of the pathway between the initial and final states of the system.
To obtain MgO safely without exposing magnesium to flame, the reaction sequence shown in the image attached may be carried out. Since the enthalpy of the overall reaction is independent of the pathway between the initial and final states of the system, the sum of the enthalpy of each step yields the enthalpy of formation of MgO.
Hydrocarbons which contain only single bonds are called alkanes. <span>This gives them a general </span><span>formula CnH2n</span>+<span>2. Given we are given eight carbon atoms then it should be that it would have 2(8)+2 = 18 hydrogen atoms. Therefore, the statement is true.</span>
Water takes longer to cool down and heat up because it detains temperature longer. So in the summer, coastal areas are cooler and the in the winter, coastal ares are warmer.
Freezing point depression is directly proportional to molality. So the compound to have the greatest effect will be the one that disassociates into the most ions = CaF2
