Which of the following is the best example of chemical weathering?

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, whi

hram777 [196]

Answer:

the change in energy of the gas mixture during the reaction is 227Kj

Explanation:

THIS IS THE COMPLETE QUESTION BELOW

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.

From thermodynamics

ΔE= q + w

Where w= workdone on the system or by the system

q= heat added or remove

ΔE= change in the internal energy

q=+ 319kJ ( absorbed heat is + ve

w= -92kJ

If we substitute the given values,

ΔE= 319 + (-92)= 227 Kj

With the increase in enthalpy and there is absorbed heat, hence the reaction is an endothermic reaction.

8 0

3 years ago

Can someone please help me with the with this

solong [7]

Answer:

Chemical

Explanation:

4 0

3 years ago

The pH pH scale for acidity is defined by pH = − log 10 [ H + ] pH=-log10[H+] where [ H + ] [H+]is the concentration of hydrogen

balu736 [363]

Answer:

2 51 × 10^-5mol/L

Explanation:

The concentration of hydrogen ions can be calculated using the formula below :

pH = -log [H+]

pH = 4.6

[H+] = ?

[H+] = Antilog (-4.6)

[H+] = 2 51 × 10^-5mol/L

7 0

4 years ago

What's ligand and how are they classified

KATRIN_1 [288]

Explanation:

Ligands: In co-ordination chemistry ligands are ion, molecule or any species which donates electron pair to central metal atom.

Depending on the type of interaction Ligands are of three types.

Sigma donor only
sigma as well as pi donor
pi acceptor ligand

let's understand each type of Ligands individually & in more detail.

1 - Sigma donor only: This is a unidirectional interaction, in which filled ligand overlaps (head to head) with central metal atom/ion & donates pair of electron in the LUMO of metal.

generally all the molecules of 2nd period without pi bond comes in this category, below are few example of sigma donor ligands,

$\small \sf NH_3, H_2O, CH_3^-, H^-, R-OH, R-NH_3, etc$

2- Pi donor: This in also a unidirectional interaction between ligand & central metal atom but the along with head to head overlap, side overlapping takes place.

generally protonated neutral molecules who have more than one pair to donate show such interaction, for e.g.

NH3 have two lone pair to donate but the energy level of both the lone pairs are different hence when it is neutral it only donates one pair of electron. but when NH3 is protonated to NH2- it have two electron pairs (negative charge+ lone pair) to donate & both the pairs have same energy level. example of such ligands are below,

$\sf \small NH_2^-, OH^-, R-O^-, R-NH^-, F^-, Cl^-, Br^- SH^- etc$

3- Pi acceptor ligand: This is a bidirectional interaction between ligand & central metal atom/ion, the filled orbital of ligand undergoes head to head to overlap with vacant orbital of central metal atom, & filled D orbital of central metal donates their pair to vacant LUMO of ligand.

depending on the LUMO pi acceptor ligands are further classified into two categories.

$d\pi - \sigma* \small \sf When \: lumo \: is \: \sigma*\\ d\pi - \pi* \small \: \sf When \: lumo \: is \: \pi*$

The dπ-σ* is seen in molecules of 3rd period onwards without pi bond for e.g.

PH3, PR3, AsR3 & SR2 etc

The dπ-π* is seen in molecules of 2nd or3rd period with pi bond for e.g.

CO C N- SC N^- etc

Thanks for joining brainly community!

8 0

2 years ago

Which of the following have a neutral charge. Electron, plasma, neutron, or proton

kupik [55]

Plasma has a neutral charge, as well as the same amount of protons and electrons put together. if the question has only one answer then it is plasma.

3 0

3 years ago