Answer : Art conservation requires minute study for the properties of a painting before it undergoes a repair work as it may help the scientist to predict the cause of damage and the areas will be identified and accordingly the damage repair work can be started off. To maintain the overall integrity of the painting intact it needs to be studied well. For repairs to be more discrete and less obstructive it has to be inspected well so that the authenticity of the painting is not lost.
Answer is: identity of the metal is gold (Au).
ω(Cl) = 35.06% ÷ 100%.
ω(Cl) = 0.3506; mass percentage of chlorine.
If we take 100 grams of the compound:
m(Cl) = ω(Cl) · m(compound).
ω(Cl) = 0.3506 · 100 g.
ω(Cl) = 35.06 g.
n(Cl) = m(Cl) ÷ M(Cl).
n(Cl) = 35.06 g ÷ 35.45 g/mol.
n(Cl) = 0.99 mol; amount of substance.
In molecule MCl₃: n(M) : n(Cl) = 1 : 3.
n(M) = 0.33 mol; amount of unknown metal.
M(M) = m(M) ÷ n(M).
M(M) = (100 g - 35.06 g) ÷ 0.33 mol.
M(M) = 196.8 g/mol; molar mass of the gold.
Answer:
Land breeze is the wind that blows cool air from land towards sea at night.
Explanation:
Land breeze is a type of wind which is cool and blows towards sea. It occurs due to the difference in the temperature of water and land. At night, the lands cool quickly due to the removal of heat from it. So the air that is present on land is cool down and this air moves towards sea. So this breez is called land breeze because it moves from land.
<u>Answer:</u> The 
for the reaction is 51.8 kJ.
<u>Explanation:</u>
Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.
According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.
The chemical equation for the reaction of carbon and water follows:
The intermediate balanced chemical reaction are:
(1) 
( × 2)
(2) 
( × 2)
(3) 
The expression for enthalpy of the reaction follows:
![\Delta H^o_{rxn}=[2\times \Delta H_1]+[2\times \Delta H_2]+[1\times (-\Delta H_3)]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B2%5Ctimes%20%5CDelta%20H_1%5D%2B%5B2%5Ctimes%20%5CDelta%20H_2%5D%2B%5B1%5Ctimes%20%28-%5CDelta%20H_3%29%5D)
Putting values in above equation, we get:
![\Delta H^o_{rxn}=[(2\times (-393.7))+(2\times (-285.9))+(1\times -(-1411))]=51.8kJ](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%282%5Ctimes%20%28-393.7%29%29%2B%282%5Ctimes%20%28-285.9%29%29%2B%281%5Ctimes%20-%28-1411%29%29%5D%3D51.8kJ)
Hence, the for the reaction is 51.8 kJ.
