Correct Answer: B) Increase of concentration of CO

Explanation

In order to understand the factors that affect the equilibrium constant of a reaction, we need to learn about Le Chatelier's principle. Le Chatelier's principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of the equilibrium will shift to counteract the change.

In the given reaction CO\(_{(g)}\) + H\(_2\)O \(\iff\) CO\(_{2(g)}\) + H\(_{2(g)}\), let's discuss how each option affects the equilibrium:

Option A: Increase of temperature

Changing the temperature of a reaction can affect the position of the equilibrium, but it does not change the equilibrium constant. This is because the equilibrium constant is only dependent on temperature. So, an increase in temperature will shift the equilibrium position, but not change the equilibrium constant.

Option B: Increase of concentration of CO(Correct)

According to Le Chatelier's principle, increasing the concentration of reactants will shift the equilibrium position towards the products, but it will not change the equilibrium constant. The equilibrium constant is a ratio of the concentrations of the products to the reactants, so changing the concentration of one reactant does not change the overall constant value.

Option C: Removal of CO\(_2\) from the mixture

Removing a product from the reaction mixture will shift the equilibrium position towards the products, according to Le Chatelier's principle. However, this also does not change the equilibrium constant, as it is still a ratio of the concentrations of the products to the reactants.

Option D: Decrease of pressure

Decreasing the pressure of a reaction will cause the equilibrium to shift in the direction that has more moles of gas, in order to counteract the decrease in pressure. In this case, since both sides of the reaction have the same number of moles of gas, a decrease in pressure will not affect the equilibrium position or the equilibrium constant.

In conclusion, although some of the options can affect the position of the equilibrium, none of them will change the equilibrium constant of the given reaction. To learn more about this, please read the relevant sections of the recommended textbooks.

Correct Answer: A. sulphur (ii) oxide

Correct Answer: B. a corrosive acid

Correct Answer: B) enthalpy change

Correct Answer: A)

\(Mg_{(s)}/Mg^{2+}_{(aq)} || Cu^{2+}_{(aq)}/Cu_{(s)}\)

Explanation

In an electrochemical cell, there are two half-cells: the anode and the cathode. The anode is the site of oxidation (loss of electrons) and the cathode is the site of reduction (gain of electrons). In this case, the overall reaction is:

\(Mg_{(s)} + Cu^{2+}_{(aq)} \rightarrow Mg^{2+}_{(aq)} + Cu_{(s)}\)

To identify the anode and cathode, we need to look at the oxidation and reduction processes happening in the reaction:

Oxidation: \(Mg_{(s)} \rightarrow Mg^{2+}_{(aq)} + 2e^-\) (Anode)

Reduction: \(Cu^{2+}_{(aq)} + 2e^- \rightarrow Cu_{(s)}\) (Cathode)

In a symbolic representation of an electrochemical cell, the anode (oxidation) is placed on the left side and the cathode (reduction) is placed on the right side. The half-cells are separated by a double vertical line (||) which represents the salt bridge that allows the flow of ions between the two half-cells. The solid (s) and aqueous (aq) species are separated by a single vertical line (/).

So the correct symbolic representation of the cell is:

Mg(s)/Mg²⁺_(aq) || Cu²⁺_(aq)/Cu(s) (Option A)

Correct Answer: D. Enthalpy of formation

Correct Answer: C) rusting of iron

Correct Answer: B. Hydra

Correct Answer: D) Making cement

Explanation

This question is asking about the uses of esters and which of the options listed is NOT a use of esters. Esters are a type of organic compound with a sweet smell and are commonly used in perfumes and nail vanishers. They are also used in making solvents for cellulose trioxonitrate(V), which is a type of explosive. However, the correct answer is option D, making cement. Esters are not used in making cement.

It is important to note that esters have other applications beyond the options listed in the question. They are used in the food industry as flavoring agents, and in the production of plastics and synthetic fibers. Esters are also important in biochemistry, where they are involved in the synthesis and breakdown of fats.

In summary, esters are a versatile class of organic compounds with various applications in different industries. While they are commonly used in perfumes and nail vanishers, they are not used in making cement.

Correct Answer: D) 70cm³

Explanation

\[\text{2H}_2(g) + \text{O}_2(g) \rightarrow 2\text{H}_2\text{O}(g)\]

From this equation, we can see that 2 moles of hydrogen react with 1 mole of oxygen to form 2 moles of water vapor. Now let's apply this to the given volumes:

We have 60 cm\(^3\) of hydrogen and 20 cm\(^3\) of oxygen. We will use the ratio of 2:1 from the balanced equation to determine the limiting reactant:

Since 20 is less than 30, oxygen is the limiting reactant.

Now let's determine the volume of residual gases. Since 2 moles of hydrogen react with 1 mole of oxygen, 40 cm\(^3\) of hydrogen will react completely with the 20 cm\(^3\) of oxygen:

There is no residual oxygen left, as it has all reacted with the hydrogen. Therefore, the total volume of residual gases is the sum of the unreacted hydrogen and the water vapor produced:

The correct answer is Option D: 70 cm\(^3\).