Correct Answer: B) Ca²⁺

Correct Answer: B) 1.0atm

Explanation

To answer this question, we need to apply Dalton's Law of Partial Pressures, which states that the total pressure of a gas mixture is the sum of the partial pressures of the individual gases.

First, let's find the mole fraction of oxygen and nitrogen in the mixture. We can do this by dividing the given mass of each gas by its molar mass.

Oxygen: \( \frac{80.0 \, g}{32.0 \, g/mol} = 2.5 \, mol \)

Nitrogen: \( \frac{56.0 \, g}{28.0 \, g/mol} = 2.0 \, mol \)

Now, we need to calculate the mole fraction of each gas. The mole fraction is the ratio of the moles of a particular gas to the total moles of the gas mixture.

Mole fraction of oxygen: \( \frac{2.5 \, mol}{2.5 \, mol + 2.0 \, mol} = \frac{2.5}{4.5} \)

Mole fraction of nitrogen: \( \frac{2.0 \, mol}{2.5 \, mol + 2.0 \, mol} = \frac{2.0}{4.5} \)

Now that we have the mole fractions, we can use Dalton's Law of Partial Pressures to find the partial pressure of oxygen.

\( P_{O_2} = X_{O_2} \times P_{total} \)

\( P_{O_2} = \frac{2.5}{4.5} \times 1.8 \, atm \)

\( P_{O_2} = 1.0 \, atm \)

So, the partial pressure of oxygen in the mixture is1.0 atm, which corresponds toOption B.

Correct Answer: A. Iron

Correct Answer: B. Adsorption

Correct Answer: D. CO2H2N2

Correct Answer: A. conversation of a soluble calcium salt to its trioxoncarbonate (lV)

Explanation

(a)(i) P=orbital are mutually perpendicular dumb-bell shaped lobes.

(ii) Methane is tetrahedral

(iii) Carbon (IV) oxide is linear.

(b)(i) Sulphur exhibits allotropy

(ii) Fe

(iii) Fe and Mg

(iv) Ne, CI, O

(v) Mg

(vi)Ne.

(c)(i) —Medical uses

— Sterilization

— Industrial uses

—Agricultural purposes

— Radioactive tracers

— Dating techniques

(ii) \(^{211} pb\) \(\to\) \(^{ 211}Bi\) + e is a radioactive reaction. It involves the production of beta particles and transmutation of Pb to Bi.

Pb --> Pb\(^{2+}\) + 2e\(^-\) is an ionisation reaction where Pb lost two electrons (oxidation) to become Pb\(^{2+}\).

(iii) Advantage: Nuclear power generation can work day and night for a few years with the same uranium fuel. Disadvantage: It is too expensive to install when compared with fossil fuels.

Correct Answer: D) margarine

Explanation

Catalytic hydrogenation of oils is a process used to convert unsaturated fats (oils) into saturated fats by adding hydrogen atoms to the fat molecules. This is done by reacting the oil with hydrogen gas in the presence of a catalyst, typically nickel or palladium, at high temperature and pressure.

The main purpose of this process is to solidify the oils, which are usually liquid at room temperature, into a more solid form. This is because saturated fats have a higher melting point than unsaturated fats due to their straight-chain molecular structure, which allows them to pack together more tightly.

In the context of the question, the correct answer isOption D: margarine. Margarine is a product made from hydrogenated vegetable oils and is used as a substitute for butter. It has a similar taste and texture to butter but contains less saturated fat and is considered a healthier option for some people.

It is important to note that the other options listed are not directly related to the catalytic hydrogenation of oils:

Correct Answer: A) involves a lot of heat when burnt

Explanation

Answer: Option A

Hydrogen is used with oxygen flames for melting metals because itinvolves a lot of heat when burnt. When hydrogen burns in the presence of oxygen, it produces water as a byproduct and releases a significant amount of energy in the form of heat. This reaction is known as a combustion reaction and can be represented by the following equation:

\[ 2H_2 + O_2 \rightarrow 2H_2O + \text{energy (heat)} \]

The high heat produced by this reaction allows for efficient and effective melting of metals, making hydrogen-oxygen flames ideal for this purpose. This property of hydrogen is especially useful in industries such as welding and metal cutting, where high temperatures are required to melt and manipulate metals.

Correct Answer: C. 5