Answer:
ΔHrxn = - 1534.3 J
Explanation:
Given the assumptions and the formula for the change in enthalpy:
ΔHrxn = m x C x ΔT, where
m is the mass of solution given 135.4 g
C is the heat capacity 4.2 J/g .K and,
ΔT is the change in temperature
we have ,
T₁ = ( 18.1 + 273) K = 291.1 K
T₂ = ( 15.4 +273) K = 288.4 K
ΔHrxn = 135.3 g x 4.2 J/gK x ( 288.4 -291.1 ) K = - 1534.3 J
After verifying our result has the correct unit, the answer is -1534.3 Joules, and the negative sign tells us it is an endothermic reaction decreasing the final temperature.
We have to get the relationship between metallic character and atomic radius.
Metallic character increases with increase in atomic radius and decrease with decrease of atomic radius.
If electrons from outermost shell of an element can be removed easily, that atom can be considered to have more metallic character.
With increase in atomic radius, nuclear force of attraction towards outermost shell electron decreases which facilitates the release of electron.
With decrease in atomic radius, nuclear force of attraction towards outermost shell electrons increases, so electrons are hold tightly to nucleus. Hence, removal of electron from outermost shell becomes difficult making the atom less metallic in nature.
Answer:
Explanation:
Coinage metals -
The group 11 elements , i.e. , Copper , Silver , Gold are called the coinage metals .
These metals are quite soft and can be easily molded to form coins . This property is called as the property of malleability .
And due its soft nature , it can easily be used to make jewelry ,
Since , making jewels require the metal to be soft and flexible ,
Hence , gold is suited the best for this .
Answer:
Calcium chloride react with aluminum to produce calcium and aluminum chloride. This reaction takes place at a temperature of 600-700°C.
CaCl2+F2 -> CaF2 + Cl2
