Answer:
1. Exothermic.
2. -1598 kJ.
Explanation:
Hello!
1. In this case, according to the reaction, we can infer that 799 kJ of energy are evolved (given off, released) it means that the enthalpy of reaction is negative as the reactants have more energy than the products; which means this is an exothermic reaction.
2. Here, as we know that the enthalpy of reaction is -799 kJ/mol, we can compute the q-value as shown below, considering the reacted 2 moles of solid iron:

Which means that 1598 kJ of energy are evolved when 2 moles of solid iron react.
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Answer:
So the molar mass of C4,H10 is
58.12g mole -1
Answer:

Explanation:
Hello there!
In this case, for the described chemical reaction, we can write:

Thus, by considering the 1:2 mole ratio of methane to water, and the molar mass of the latter (18.02 g/mol), the following is useful to calculate the mass of water that is produced:

Which is equal to:

Which is not among the choices.
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Answer:
Explanation:
To slow down this reaction, we can use any of the methods listed below:
- Increase the size of the magnesium by using solid lumps of the metal. This will take a much faster time to react than powered and granulated magnesium.
- Reduce the concentration of the acid.
- Let the reaction take place at a much lower temperature than that given.
These conditions will slow down a chemical reaction.
Answer:
The volume of a given amount of gas is inversely proportional to its pressure when temperature is held constant (Boyle's law). Under the same conditions of temperature and pressure, equal volumes of all gases contain the same number of molecules
Explanation: