Where is the word problems? Like the problems that you have to put it in.
Explanation:
The correct answer is B. Solubility describes the amount of solute that can be dissolved in a solvent. This value is not constant is affected by many factors. One factor is the temperature. An increase in temperature, a corresponding change in solubility also can be observed. The increase leads to a decrease in the solubility and the opposite. A decrease is observed since gas molecules are now has enough energy to escape the liquid phase and go to the gas phase.
For the reaction 2 K + F2 --> 2 KF,
consider K atomic wt. = 39
23.5 g of K = 0.603 moles, hence following the molar ratio of the balanced equation, 0.603 moles of potassium will use 0.3015 moles of F2. (number of moles, n = 0.3015)
Now, following the ideal gas equation, PV = nRT
P = 0.98 atm
V = unknown
n = 0.3015 moles
R = 82.057 cm^3 atm K^-1mole^-1 (unit of R chosen to match the units of other parameters; see the reference below)
T = 298 K
Solving for V,
V = (nRT)/P = (0.3015 mol * 82.057 cm^3 atm K^-1 mol^-1 * 298 K)/(0.98 atm)
<span>
solve it to get 7517.6 cm^3 as the volume of F2 = 7.5176 liters of F2 gas is needed. </span>
Answer:
-1815.4 kJ/mol
Explanation:
Starting with standard enthalpies of formation you can calculate the standard enthalpy for the reaction doing this simple calculation:
∑ n *ΔH formation (products) - ∑ n *ΔH formation (reagents)
This is possible because enthalpy is state function meaning it only deppends on the initial and final state of the system (That's why is also possible to "mix" reactions with Hess Law to determine the enthalpy of a new reaction). Also the enthalpy of formation is the heat required to form the compound from pure elements, then products are just atoms of reagents organized in a different form.
In this case:
ΔH rxn = [(2 * -1675.7) - (3 * -520.0)] kJ/mol = -1815.4 kJ/mol
Ra (radium) is the most reactive
