Answer: 8855 Joules energy is released when 115 g of 
changes from a liquid to a solid at its freezing point.
Explanation:
Latent heat of freezing is the amount of heat released to convert 1 mole of liquid to solid at atmospheric pressure.
Amount of heat released to freeze 1 gram of = 77 J/g
Mass of given = 115 gram
Heat released when 1 g of is freezed = 77 J
Thus Heat released when 115 g of is freezed =
Thus 8855 Joules energy is released when 115 g of changes from a liquid to a solid at its freezing point.
Explanation:
Note: Molar masses of elements can be found online or in the periodic table.
Moles of Magnesium
= 3.60g / (24.3g/mol) = 0.148mol.
Moles of Chlorine
= 10.65g / (35.45g/mol) = 0.300mol.
Mole ratio of Magnesium to Chlorine
= 0.148mol : 0.300mol = 1 : 2.
Hence we have the empirical formula MgCl2.
Moles of Lithium
= 9.1g / (6.94g/mol) = 1.311mol.
Moles of Oxygen
= 10.4g / (16g/mol) = 0.650mol.
Moles ratio of Lithium to Oxygen
= 1.311mol : 0.650mol = 2 : 1.
Hence we have the empirical formula Li2O.
Answer:
-179.06 kJ
Explanation:
Let's consider the following balanced reaction.
HCl(g) + NaOH(s) ⟶ NaCl(s) + H₂O(l)
We can calculate the standard enthalpy change for the reaction (ΔH°r) using the following expression.
ΔH°r = 1 mol × ΔH°f(NaCl(s)) + 1 mol × ΔH°f(H₂O(l)) - 1 mol × ΔH°f(HCl(g)) - 1 mol × ΔH°f(NaOH(s))
ΔH°r = 1 mol × (-411.15 kJ/mol) + 1 mol × (-285.83 kJ/mol) - 1 mol × (-92.31 kJ/mol) - 1 mol × (-425.61 kJ/mol)
ΔH°r = -179.06 kJ
A physical property is what a substance is like; it's directly observable. On the other hand, a chemical property is how a substance behaves; its reactivity.
Examples of a physical property are: color, texture, boiling point, freezing point, and melting point.
Examples of a chemical property are: flammability, combustion, and formation of a precipitate.
Answer: option A. 350 K and 0.30 atm
Explanation: a gas behaves as an ideal gas at higher temperature and low pressure
