Answer:
-145.2kJ
Explanation:
Enthalpy is an extensive property as its value depends on the amount of substance present in the system.
If the enthalpy for one mole of methanol = -726 kJ/mol;
The Enthalpy for 0.2 mol is given as;
Enthalpy = 0.200 * 726
Enthalpy = -145.2kJ
It would take -145.2kJ for 0.200 mol of methanol to undego the combustion reaction.
Answer:
Here are some of the differences between a mixture of iron and sulfur, and iron sulfide: the mixture can contain more or less iron, but iron sulfide always contains equal amounts of iron and sulfur. the iron and sulfur atoms are not joined together in the mixture, but they are joined together in iron sulfide.
Explanation:
The correct answer would be the fourth option. Hydrochloric acid has a higher boiling point than fluorine molecule because the former is a polar molecule which means that it has stronger bonds than fluorine which is a non-polar molecule. Stronger bonds require more energy to break these bonds.
Answer: Metals bond with metals.
Explanation: A metallic bond is a sharing of electrons between many atoms of a metal element. Metallic bonding is when positive ions (metals) are in a 'sea of negative electrons'. The electrons are delocalised, which means they can move around easily and carry charge, and this enables it to conduct electricity, even in a solid state. The big pool of electrons is like a free-for-all in that any valence electron can move to any atom within the material.
The correct options are as follows:
1. A.
A synthesis reaction is a type of reaction in which two or more reactants combine together to form only one product. Synthesis reaction always release energy in form of light and heat, therefore, they are usually exothermic reactions. In the option given in A, nitrogen and nitrogen combine together to form ammonia; this is a synthesis reaction.
2. D
A radioactive half life refers to the amount of time it will take for half of an original radioactive isotope to decay.
In the question given above, the half life of the element is 1000. Thus, in 1000 years only half of the original amount will remain. In another 1000 years only 1/4 of the original amount will remain and in another 1000 years only 1/8 of the original amount will remain. Therefore, it will take 3 half lives before 1/8 of the original sample remain.<span />
