Halogens are elements that can be found in group 7 of the periodic table. They have 7 electrons in their outer shell and thus can form only a single covalent bond with other elements. Examples of halogens include chlorine, bromine and fluorine. A carbon compound that is covalently bonded with chlorine or bromine is called a halocarbon.
Equation a. C3H8(g) + O2(g) → CO2(g) + H2O(g) + 2220 kj
is endothermic. + 2220 kj
Equation b. 2 Na(s) + Cl2(g) → 2 NaCl(s) + 819kJ
is also endothermic since the overall energy change is positive. + 819kJ
The equation c. PCl5(g) + 67kj → PCl3(g) + Cl2(g) is endothermic since it requires anergy to proceed.
Answer: The bulk of liquids separate from the standard substance through crystallization, creating a crystalline block.
Freezing is almost often an exothermic mechanism which ensures that heat is emitted when liquid transforms into concrete.
The energy emitted after freezing, known as the fusion enthalpy, is a latent heat, which is precisely the same as the energy used to melt the same volume of solid.
Answer: 1.32
Explanation:
Given
85 gm of sulfur dioxide is present at STP
The molar mass of sulfur dioxide is 
The number of moles of sulfur dioxide is

He did experiments with combustion and gas's