The molecules in liquid water are held together by relatively strong hydrogen bonds and its enthalpy of vaporization, 40.65 kJ/mol is more than five times the energy required to heat the same quantity of water from: 0 °C to 100 °C (cp = 75.3 J K−1 mol−1).
Hope this helps.
I would say d. average of the mass number and the atomic number for the element.
It has two elements.
Magnesium shows +2and Cl shows -1.
Answer:
Oxygen is the most contain in earth but you asked in a,b,c and d. So I'll choice A. aluminium.
Answer:
ΔH rx = -43.5 kJ / mol
Explanation:
In water, Xdissolves thus:
X(s) + H₂O(l) → X(aq) + H₂O(aq)
It is possible to find the heat in dissolution process using coffee cup calorimeter equation:
Q = -m×C×ΔT
<em>Where Q is heat, m is mass of solution (35.0g -density 1g/mL- + 2.20g = 37.2g), C is specific heat of solution (4.18J/g°C), and ΔT is change in temperature (26.0°C-15.0°C = 11.0°C)</em>
Replacing:
Q = -37.2g×4.18J/g°C×11.0°C
Q = -1710J = -<em>1.71kJ</em>
As enthalpy is the change in heat per mole of reaction, moles of X that reacted were:
2.20g X × (1mol / 56.0g) = <em>0.0393 moles</em>
As heat produced per 0.0393moles was -1.71kJ, heat per mole of X is:
-1.71kJ / 0.0393mol = -<em>43.5 kJ / mol = ΔH rx</em>
