Answer:
The enthalpy change for the given reaction is 424 kJ.
Explanation:

We have :
Enthalpy changes of formation of following s:



(standard state)
![\Delta H_{rxn}=\sum [\Delta H_f(product)]-\sum [\Delta H_f(reactant)]](https://tex.z-dn.net/?f=%5CDelta%20H_%7Brxn%7D%3D%5Csum%20%5B%5CDelta%20H_f%28product%29%5D-%5Csum%20%5B%5CDelta%20H_f%28reactant%29%5D)
The equation for the enthalpy change of the given reaction is:
=

=


The enthalpy change for the given reaction is 424 kJ.
Answer:
When the operation of the voltaic cell, which is formed of an aluminum and silver strip takes place, the atom of aluminum loses three of its electrons and the Al3+ formed moves within the solution. The Al3+ ion gets dissolved within the solution and the electrons lost in the process moves through the wire and get acquired by the ions of silver, which then get reduced to solid Ag resulting in the mass gain of silver strip.
Answer : The new pressure acting on a 2.5 L balloon is, 8.6 atm.
Explanation :
Boyle's Law : It is defined as the pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.

or,

where,
= initial pressure = 3.7 atm
= final pressure = ?
= initial volume = 5.8 L
= final volume = 2.5 L
Now put all the given values in the above equation, we get:


Thus, the new pressure acting on a 2.5 L balloon is, 8.6 atm.
Earthworms influence (and benefit) the soil ecosystem in a number of ways: Recycling organic material: Earthworms, along with bacteria and fungi, decompose organic material. ... Improving soil structure: Earthworm burrows alter the physical structure of the soil. They open up small spaces, known as pores, within the soil.
Hydrogen gas(H2) has a molar mass of 2 g. Molar mass of a substance is defined as the mass of 1 mole of that substance. And by 1 mole it is meant a collection of 6.022*10^23 particles of that substance.
So number of moles of H2 are 0.5 in this case. And thus it means there are (6.022*10^23)*0.5 particles( here they are molecules) in 1g of H2.