Answer:
option C= A positive ion is attracted to negative ion
Explanation:
Ionic bond:
Ionic bond is formed when oppositely charged ions attract each others i.e negative and positive ions.
we know that a neutral atom consist of equal number of proton and electron, cancel the charge of each other that is equal in magnitude and make the atom neutral or we can say that net charge is zero.
But when the atom lose or gain the electron, imbalance of neutron electron occur so charge will not remain zero and atom is no more to be said neutral.
For example:
Take the example of sodium that can lose one electron and form Na+. This Na+ ion is called cation because it carry positive charge by losing the one electron. This cation now contain eleven proton and ten electron.
Now consider the example of Chlorine atom. It consist of 17 proton and 17 electron. But in order to attain the noble gas configuration or to complete the octet it gain one electron and form anion (Cl-). The chlorine anion consist of 17 proton and 18 electron.
Now consider the sodium chloride which is an ionic compound. It is formed by the complete transfer of electron from sodium to chlorine atom and form ionic bond. In this ionic compound sodium carry positive charge and chlorine carry negative charge there is attraction between these oppositely charged atoms.
42cubic centimeter are in the block
volume is 48
One is closer to the equator so be must be warmer
After 3 half life periods you would have 5 grams of krypton left because half of 40 is 20 half of 20 is 10 and half of 10 is 5
<span>Answer:
he strong acid- strong base reaction should give more energy.
So why is the heat of neutralization (enthalpy) of a strong acid such as HCl with a strong base like NaOH more than the heat of neutralization of a weak acid, such as acetic acid with NaOH?
The enthalpy of neutralization of an acid by a base is defined as heat change when one gram equivalent of acid is neutralized by a base ,the reaction being carried out in dilute aqueous solution ... enthalpy of neutralization of base by an acid is defined in a similar manner...
for example when 1 gram equivalent of HCl is neutralized with NaOH 57.1 kj of heat is produced .. HCl (aq) + NaOH (aq)----> NaCl (aq) + H2O (l)... H = -57.1 kj/mole
hence enthalpy of neutralization of HCl with NaOH is 57.1 kj enthalpy of neutralization of any strong acid (like HCl,HNO3,H2SO4) with a strong base (like LiOH,NaOH,KOH) or vice versa is always the same i.e. 57.1 kj...this is because strong acids ,strong bases and salt that they form are all completely ionized in dilute aqueous solutions ...thus the reaction between any strong acid and strong base for example in the above case may be written as :
NaOH (aq) + HCl(aq) -----> NaCl (aq) + H2O (l)... H = -57.1 kj/mole
they will dissociate as :
Na(+) (aq) + OH(-) (aq) + H(+) (aq) + Cl(-) (aq) ---> Na(+) (aq) + Cl(-) (aq) + H2O (l)
common ions will cancel out..
H(+) (aq) + OH(-) (aq) ----> H2O (l)
thus neutralization is simply a reaction between H(+) ions given by acids and OH(-) ions given by base to form one mole of H2O.....since strong acid and strong base completely ionize in aqueous solution number of H(+) and OH(-) produced by 1 gram equivalent of strong acid and strong base is always the same ...hence enthalpy of neutralization between a strong acid and strong base is always constant...
if either the acid or base or both are weak the enthalpy of neutralization is less than 57.1 kj ...the reason for this behaviour can be explained by considering the neutralization between a strong base like NaOH and weak acid like acetic acid.. now acetic acid ionizes to a small extent whereas NaOH ionizes completely as :
NaOH (aq) ----> Na(+) (aq) + OH(-) (aq)
CH3COOH (aq)<--------> CH3COO(-)(aq) + H(+)(aq)
(an equilibrium) when H(+) given by acid combine with OH(-) given by base the equilibrium shifts to right (in accordance with Le Chatelier's principle) ,so more of acetic acid dissociates ...a part of heat produced during combination of H(+) and OH(-) ions is used up for complete dissociation of acetic acid ...the heat thus used up is called enthalpy of dissociation or enthalpy of ionization ..it is 1.9 kj for acetic acid...hence net heat evolved in above reaction is 57.1 - 1. 9 = 55.2 kj ...which less than that evolved in strong base and strong acid reaction.</span>
