changing the temperature and increase in the pressure
Change in concentration, pressure, catalyst, inert gas addition, etc. have no effect on concentration, pressure, catalyst, inert gas addition lead to a shift in equilibrium position .
In general, a reaction is said to be at equilibrium when the rate of consumption of the reactants equals the rate of formation of products. The dynamics of this state can be represented in terms of the 'equilibrium constant', Keq which is the ratio of the concentration of products to that of the reactants.
Consider a hypothetical reaction:
A ↔ B
Based on the above equation, the value of Keq should increase if the concentration of B i.e. the product is decreased. However, if concentration of B is decreased then based on Le Chatelier's principle, the equilibrium will shift in a direction to produce more of B such that a new equilibrium is established and Keq remains undisturbed. This is also the case for changes in pressure.
It is only by changing the temperature does the value of Keq change.
b. the layer of oxide formed on statues made of metal
Explanation:
Chemical weathering is a process whereby rocks are disintegrated or weathered causing a chemical reaction thereby leading to change in the parent rock constituents .
In chemical weathering a new substance is usually formed after the weathering takes place.
From the question the layer of statue made by metal will likely form oxides of those metals. Example Silver will react with oxygen to form an entirely new substance like silver(i)oxide.
Taking into account the definition of calorimetry, 0.0185 moles of water are required.
<h3>Calorimetry</h3>
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).
So, the equation that allows to calculate heat exchanges is:
Q = c× m× ΔT
where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
<h3>Mass of water required</h3>
In this case, you know:
Heat= 92.048 kJ
Mass of water = ?
Initial temperature of water= 34 ºC
Final temperature of water= 100 ºC
Specific heat of water = 4.186
Replacing in the expression to calculate heat exchanges:
92.048 kJ = 4.186 × m× (100 °C -34 °C)
92.048 kJ = 4.186 × m× 66 °C
m= 92.048 kJ ÷ (4.186 × 66 °C)
<u><em>m= 0.333 grams</em></u>
<h3>Moles of water required</h3>
Being the molar mass of water 18 , that is, the amount of mass that a substance contains in one mole, the moles of water required can be calculated as:
We first calculate the heat released: Specific heat = 3.21 kJ/kgK Heat released = heat absorbed by calorimeter Heat absorbed = mcΔT = 1.9 x 3.21 x 4.542 = 27.7 kJ
Now, we calculate the moles of hexane present: Moles = mass / Mr moles = 0.58 / (12 x 6 + 14) = 0.0067